Little treasures: dwarf Polygala species

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While waiting for Hepatica seeds to drop into the catching bags, ;) we can admire two dwarf Polygala species. I’m a big fan of Polygalas.

From the garden, flowering for the first time: Polygala amarella, the dwarf milkwort. This is a European species growing on limestone grasslands, slopes and rock ledges, up to subalpine level.

Polygala amarella, cultivated (grown from seeds wild coll. Carpathian Mts)

From our woods: Polygala paucifolia, the gaywings. I showed it many times but it flashes for attention, flowering more or less at the same time with Trillum grandiflorum. It is growing on deciduous and mixed forests, in part-shaded, slightly moist locations.

Polygala paucifolia in wild habitat

Polygala species are not difficult to grow from seeds, it is just that the seeds are very hard to “catch” and thus always in short supply; then the seedlings are best grown in the community pot for 2 years. Flowering can start in the third year and is very rewarding. Polygala vulgaris and P. major are also in line to flower this summer — it doesn’t get any better!

Timeline for Hepatica seeds: collecting maybe in the first week of June.
The offerings are taking shape in the Seeds Shop – check out the Hepatica category; final price/seeds per pck. will be established after collecting.

 

 

Hepatica americana and a checklist

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As soon as the rains allow, small bags will be placed to catch the Hepatica seeds; for both H. americana and H. acutiloba. I mentioned before that catching the seeds is not an easy task. This year the flowering show was partially missed and we cannot be sure about the seeds until later. I will show a few H. americana plants that I have my eyes on:

Hepatica americana #1
I gave it this ‘name’ a few years ago and in a way it remains my favorite. It is a large specimen, reliable flowering (seeds germinating in the first spring) with violet/blue flowers with a narrow white edging.

Hepatica americana ‘#1’

H. americana #1 foliage

H. americana ‘Spring Dawn’
An exciting find with larger than usual flowers with multipetal tendency and also gorgeous foliage. It is a mesmerizing form of H. americana but I don’t know yet if it would come true from seeds.

Hepatica americana ‘Spring Dawn’

H. americana ‘Spring Dawn’ fading flowers

Few forms with pure, white flowers are also marked for collecting.


A bicolor specimen shown below it would be a first time offering. As well, seeds from a small isolated group of plants with white flowers brushed with pink, they should come true from seeds – a seedling in the featured picture.

Hepatica americana bicolor

Maybe also few seeds from a white form and white/lavender forms with multipetal tendency.

H. americana multi white

H. americana 5a-B19

Available seeds will be posted in the shop (in 2-3 few weeks) and announcement will be made here and on FB page (those interested please subscribe to one of them).
Last year extremely cold and rainy spring made it for a disastrous seeds setting so I really hope this season will be better. Fingers crossed!

The checklist posted for H. acutiloba also applies for growing Hepatica americana from seeds.

 

 

Hepatica acutiloba 2020 and a checklist

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What else better on a cold Friday than to look at nice Hepatica acutiloba pictures? This spring the flowering show was partially missed, but there are plenty of pictures from previous years. What forms will be available on the shop is hard to say until the seeds start to form. We can only hope that most will have a good seeds set.

Again, collecting Hepatica seeds is not an easy task. Especially in the wild it requires repeated trips and bagging (this must also be done in the garden) in order to catch the rapidly dispersing seeds.

I would very much like everyone to be successful in growing these beautiful plants. Truth is though, that not everyone has enough patience (and/or skills) to grow from seeds species that require 3+ years to reach a modest flowering stage. So, I put together a checklist.
Checklist for growing Hepatica from seeds; you have to mark OK for all in order to consider growing Hepatica from seeds.
– purchase the seeds preferably as soon as they become available.
– sow the seeds as soon as they arrive, keep the pots under natural conditions in a part-shaded location and water as necessary.
– be prepared to wait until the second spring for germination; i.e. take care one more year of “empty looking” pots.
– transplant and take care of small seedlings.
– wait 2-3 more years to see the first flowers.
– all of the above, while continuing to take care of the plants/pots (they can be also ‘planted’ in the ground/large container)
– all in all, 3-4 years are necessary until able to enjoy the first flowers.

H. acutiloba multi-white

Hepatica acutiloba multi-pink

Hepatica acutiloba fo.rosea

Hepatica acutiloba spring foliage

Hepatica acutiloba foliage

Hepatica acutiloba ‘Purple Star’

Hepatica acutiloba pastel mix3

Hepatica acutiloba pastel mix

Hepatica-acutiloba-pastel-mix6

Hepatica acutiloba 2A-B18

Hepatica acutiloba white, scented

Hepatica acutiloba woodland

More details on Hepatica page, also Transplanting and caring for Hepatica seedlings, plus see the linked posts below.
Again, there will be an announcement with more details when seeds become available (late May-early June).

 

Growing Hydrastis canadensis; work with nature

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Today, I continue to record the cultivation of goldenseal, Hydrastis canadensis, in my garden. A reminder that this is an endangered species in its wild habitat! Last year one plant even produced a small fruit and what to do with few seeds? I sowed them of course; now they are starting to germinate, on the same time the adult plants are emerging from the ground.

The beautiful sight of Hydrastis canadensis emerging from the ground yesterday, May 4th 2020

Especially when growing native species it is important to work in sync with nature in your garden. This is also a good occasion to let you know that there is a wealth of good gardening eBooks on sale until May 21.

Those interested, please see the link below for the Earth Day Special on ALL gardening eBooks!
https://www.gardenfundamentals.com/special-on-hundreds-of-gardening-ebooks/

 

 

Spring in time of Covid V – native species

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A brief garden ‘woodland’ walk to see various species that were basking under the sun a couple of days ago. Again, trying to use locations in the garden that reproduce the native habitat is the key to happiness.
For most parts this means deciduous woods which allow plenty of sun in early to mid -spring and again in the fall. Combined deciduous/coniferous woods allow less light and can also be dryer (except on bottom lands and river valleys).

Of course that some species are more adaptable than others and having seedlings you can try them in various locations to see how they react.
Asarum canadense, the wild ginger, is one of the most easy going species that can be used as a groundcover. I caught it in the act of flowering in a sunny position, while in more shaded area is still in bud. The second picture shows the success I had establishing young plants grown from seeds on a dry slope (also shoots of Maianthemum stellatum showing up).

Asarum canadense, April 2020

Aasarum canadense on a slope


Anemonella thalictroides  (syn. Thalictrum thalictroides), rue anemone, is usually found on slightly moist locations. It is very easy to grow from fresh or moist packed seeds – pictured here are 3 years old flowering plants.

Anemonella thalictroides, garden April 27

Thalictrum thalictroides (Anemonella), May woodland

Another easy going, spreading by self-sowing is Hydrophyllum virginianum, Virginia waterleaf. It can even grow close to old tree trunks (hint for dry shade resistance!). A most loved species by the bees and bumblebees, so a few plants are a must (young seedlings can be easily removed if not desired).

The spring beauty, Claytonia virginica always loves to be close to the trees. A few left in my garden (squirrels love to dig the corms) and a nice patch flowering in the woodlands last year. The woods are still out of reach and seed collecting remains a question mark for now.

Hydrophyllum virginianum, garden April

Hydrophyllum virginianum, woodland

Claytonia virginica, garden

Claytonia virginica

 I will finish for today with these Prosartes lanuginosa seedlings, which are grown in a pot buried in the ground. I have shown this easy method to grow all woodland species from seeds a few times and I repeat it again for all those who recently purchased Caulophyllum thalictroides seeds ;)

Prosartes lanuginosa seedlings, yellow mandarin

Read more about easily growing woodland species from seeds: We got the moist packed seeds – now what?
Purple beasties – Caulophyllum

Until next…

 

Spring in time of Covid IV: native species

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In the last few days I’ve been ‘circling around’ a garden bed which due to the natural land configuration remains temporarily wet, with gradients of wetness and sun to part/sun exposure.
With the warming up I will start adding more species to this area. So let’s see a few native species suitable for such a location. When growing native species (and not only) it is very important to choose a garden spot that best imitates their native habitat.

Iris versicolor (Northern blue flag) is more than happy in such a location; the wetter, the better. Also, a small clump of Iris hookeri will be moved closer hoping for a better flowering. I plan to also try in this location a division of our beautiful dwarf lake Iris, Iris lacustris, which is currently in a drier spot.

Iris versicolor, April

Iris versicolor, late April, May

Iris hookeri, April

Iris hookeri

Iris lacustris, April

Iris lacustris late April/May

Sisyrinchium mucronatum, the slender blue–eyed grass, it is another resident; easy to grow and its fine texture combines beautifully with the Iris leaves.
Parnassia glauca (Marsh grass of Parnassus); any slightly moist place shouldn’t be without a Parnassia! This species gets quite robust after a few years and may even reseed in place. And what a wet area would be without water avens, Geum rivale?

Sysirinchium mucronatum, early April

Sisyrinchium mucronatum, June

Parnassia glauca, summer

Geum rivale, water avens

A bunch of Zigadenus elegans (Mountain death camass) seedlings planted last fall are just coming up. Also, speaking about seedlings, a pot of Lilium philadelphicum (wood lily) awaits the spring planting rush to begin.
One can find this native Lilium in various habitats, including (moist) woodland edges, but I’ve also seen beautiful specimens growing in wet ditches and I will try it this way.

Lilium philadelphicum seedlings

Lilium philadelphicum, summer

Lilium philadelphicum

There are many more other native species that I will gradually add: Castilleja coccinea and Lobelia cardinalis (seeds to be sown ‘in situ’ by fall). Asclepias incarnata is a must, as are Lobelia spicata and Chelone obliqua if the space allows (to mention just a few…).
Grasses and sedges speaking, there is a nice Deschampsia cespitosa (tuft hair grass) and Carex grayi; I would definitely like to grow more grasses.

Take notes for fall sowing ;) and fingers crossed seeds will be collected.

Castilleja coccinea

Asclepias incarnata

Lobelia cardinalis

Lobelia spicata

Carex grayi

Chelone obliqua

 

Spring in time of Covid III: native species

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The first Hepatica started to flower a while ago bringing high hopes of an early spring. Then, cold, bitterly temperatures returned in Ontario and everything has come to a halt. Taking pictures it is always a good way to record the start of growth for various species in the garden and in the wild. It is not only about the pretty flowers ;)

But records apart, I admit it is mostly about the joy seeing the first new shoots and leaves appearing from the ground. After our cold and long winters, the feelings of anticipation and expectation that an early spring brings can hardly be replaced by anything else.

Leaving Hepatica and Caulophyllum aside, I will show early starting NA native species from the garden (most were grown from seeds). The first picture in the gallery is from the garden; second one from the garden or woodland later in the spring/summer (hover for names).

First, the evergreen Geum triflorum (Prairie smoke). It retains a decent foliage all winter long and at the first spring signs will grow new foliage and start flowering. It is quite amazing to have these healthy looking, large clumps in April!

Geum triflorum in April

Geum triflorum in June

Allium tricoccum (Wild leeks, ramps) foliage; mine are young and may not flower this year.

Young Allium tricoccum in April

Allium tricoccum woodland colony, June

Podophyllum peltatum (Mayapple) little umbrellas, as well as the first Sanguinaria canadensis(Bloodroot).

Podophyllum peltatum, April

Podophyllum peltatum colony, June

Sanguinaria canadensis, April

Stylophorum diphyllum (Woodland poppy) emerges with the flower buds, well prepared for an early flowering in May.

Stylophorum diphyllum, April

Stylophorum diphyllum

In the feature image: our beloved Primula mistassinica; this species retains a small rosette over the winter and the flowering stems start growing in early spring.

Primula mistassinica April

Primula mistassinica, late April/May

The native species April-fest will continue soon after I prepare more pictures.
*Note: links are provided for those interested to read more about the species, but of course seeds are not available for many at this time.

 

Caulosaurus

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Young Caulosaurus :)

While talking Caulophyllum, here’s something I didn’t get around to show in late September last year: a bunch of Caulophyllum (most probably giganteum) 2 years old seedlings I dug out to replant.

 

As mentioned before, the large seeds of Caulophyllum, which require 2 years for germination, can be easily sowed ‘in situ’ (in the garden, woodland floor) in a shaded area, preferably close to another perennial/shrub. During dry spells some watering is required; otherwise there is nothing else to do.
When ready, they will germinate. If sown well-spaced there is no need to transplant them.

One early spring pleasure is to see the purple shoots erupting from the woodland floor. I still hope to be able to do it. Until then, the little ones from the garden are doing a good job.

 *Attention to the clients who have purchased seeds 4 years ago as C. thalictroides: it is very probable you actually have C. giganteum.

Caulophyllum giganteum seedlings: all seen here were sowed/ growing too close together; it was a good time to dig them up and replant them properly in September

 

 

Transplanting/caring for young Hepatica seedlings 

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We talked about seeds and  Hepatica germination – we need to have patience. Not only the seeds may germinate in the second year after sowing even if they were kept moist, also the seedlings, in most cases, are not very fast to develop.  Some will remain at the cotyledon leaves stage in the first season, others will grow one true leaf. In either case, they can be quite tiny and intimidating.

Let’s see about transplanting.

When to transplant?
One feature of Hepatica is that they put up a good growth in the spring through summer (roots, leaves, seeds, future flower buds) and then they take a ‘break’ until next year. For this reason I like to transplant in early spring or if not, in the fall; at least, the young plants will start the next season already well prepared.

What potting mix to use?
There are various recipes recommended by Hepatica growers. Unfortunately, most are not easy to reproduce exactly here. I’ve tried to mix various products available in the last years and some were better than others. What I want in the end is to have an easy to reproduce recipe using soil brands anyone can buy (in Canada).

I came up with this mix, which I think is pretty good: mix all ingredients in equal parts (1:1:1)
Perlite
Pro-mix potting soil
All-purpose potting mix:  Fafard brand is a good one. Unfortunately this sector of the landscape industry is non-regulated and most brands don’t specify the contents of the potting mix, plus, in almost in all cases they contain too much peat.

As a rule, as long as good drainage is ensured all should be well, so other combinations could be tried.

 Pots

Taller pots are preferable. You can basically use any type/size of pot proportionally sized in regards to the seedlings size and transplant 1-2 seedling/pot.
To avoid handling many individual small pots one can also use a rectangular planter instead. Another option is a compact-tray with a good height.

Hepatica americana container seedlings

Hepatica americana seedlings

Transplanting
Remove the seedlings from the sowing pot and carefully separate them. As seen in the pictures, Hepatica seedlings have a fine root system.
Transfer the seedlings in a new pot, add mix and take care to press only around the roots. The watering will settle down the mix well (add more mix if necessary).

Clockwise: Hepatica acutiloba pastel mix – seedlings removed from the pot; Hepatica japonica transplanted, flowering seedling, H. acutiloba pastel mix seedlings showing the roots; compact-tray with H. nobilis and H. acutiloba seedlings

Location: same like for adult plants, keep the pots/trays in a location with plenty of sun in the spring and shade starting summer. If necessary cover them with a plastic mesh. Water when necessarily (deep watering and let dry between) if the pots are not exposed to rain; a light fertilizer during the spring growth is beneficial.

Planting in the ground:
Usually in the third year the seedlings  can be planted in the ground.
To continue growing in pots transplant again to a larger size pot/container. Hepatica species are fitted for container growing if you have a small garden, or unsuitable soil conditions. You can easily provide sun in the spring and shade starting summer by moving the container in different spots.

Most often also the first flowers will appear in the third year to reward your efforts!

Various forms of Hepatica japonica 3 years-old plants

*I referred in general to Hepatica because in the end there is no difference between various species when it comes to germinating the seeds and transplanting (H. americana, H. acutiloba, H. nobilis, H. japonica and H. henryi).

FAQ – Hot water treatment

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We discussed last year about the hot water treatment, a very easy to apply germination method which can successfully replace the use of scarification for the Fabaceae species. However, it is hard to say if it would be effective for all species and if all species will germinate at room temperature afterwards.

In addition, I will provide answers to few common questions and plates with seeds images for all species/genera I personally tried/try with this method.

How much the seeds should/will swell after a hot water treatment?
It depends on the species, the size and shapes of the seeds varies greatly, but usually the seeds can increase in size 2-3 times than the original size. Sometimes you may notice a ‘dramatic’ change in the seeds aspect/size (ex. Lupinus breweri).

Is it possible that no seeds will swell after 1 treatment?
Yes, it can happen, repeat again (for ex. Senna hebecarpa, Oxytropis, Trifolium seeds are slow to react).

How much time should the seeds remain in water?
Usually the next day you will see if the seeds have swollen (and how many), but to be sure you can keep them in the water for 2-3 more days (change the water daily).
In extreme case, seeds may even start to germinate in water after a while! (Hedysarum, Thermopsis).

Will all the seeds swell at once?
No, in the majority of cases after the first treatment only a few seeds will swell. Sow the swollen seeds after each treatment and repeat for the others (2-3+ times).

How soon will the seeds germinate?
It varies greatly with the species, some will start to germinate in few days, others will take a longer time (for ex. various Baptisia were slow to germinate).

Fabaceae – Hot water treatment 2019; notice the increase in size and the differences between species; all were germinated at room temp. afterwards

Current trials:

Fabaceae – Hot water treatment 2020; seeds aspect after 2 treatments. For each species notice seeds still of normal size and also swollen seeds.

 

 

Sowing advice for springtime

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With the first snowdrops in bloom spring is undeniably in the air. It is an exciting time with renewed hope and we all think about new plants to add in the garden.
Some people plan well ahead about what to grow from seeds, but others maybe purchase seeds and plants on the impulse of the moment. Then, there are always seeds arriving late from seeds exchanges.

Because all the latest orders had in common a combination of species, warm and cold germinators, I feel obliged to repeat how to proceed at this time in order to obtain the best results with minimum effort. Good timing for sowing is important!
If you don’t need advice, jump to the end of the post to see a few ‘green things’ from the garden :) All grown from seeds, except the snowdrops.

For those in the Northern Hemisphere
Species that are indicated to germinate at warm (15-20C) can be sown right away if you use indoor lighting for growing seedlings or later (April/early May) if you intend to keep the pots outdoor.

*Species indicated to have double dormancies and require first a slightly warm cycle, followed by a cold one in order to germinate (Hydrophyllum, Euonymus, Actaea…) – can be sowed later, in the summer. Most Peonies are also in this category; sowing in late June/July gives them more than enough time to develop the roots until late fall. Same goes for two stage warm germinating Lilium species (L. michiganense, L. monadelphum…).

Various Fabaceae can be treated with the ‘hot water treatment’ and considered warm germinators. Last year tests gave excellent results (Hedysarum, Oxytropis, Astragalus, Baptisia, Thermopsis, Lupinus*).

Species that can be sowed ‘in situ’ (Papaver, Lobelia, some Viola spp.…) – wait until April/early May and cast the seeds in place, incorporating lightly (most such seeds are fine and need light to germinate), keep the area moist and if there are too many critters around consider placing a mesh on top of the sowing location.

Species indicated as: sow in the fall or cold/moist stratification – I advise you to keep the seeds packets in the fridge until fall, and then proceed with sowing (in pots or ‘in situ’).

You can of course try to provide cold/moist stratification in the fridge, but don’t expect the same good results. Also, you may end up with seeds germinating in June/July and young seedlings by late fall withstanding poorly the winter cold.

 Moist packed seeds: not sold at this time of the year, with the exception of two years germinators (Caulophyllum, Medeola), when stock supply and temperatures allow.

Cypripedium: if not using ‘in vitro’ equipment, as discussed already, there is a slight chance that by incorporating the seeds in the garden close to where other orchids thrive, to be successful. Note the ‘slight chance’.

Those in the Southern Hemisphere: reverse the timings, sow the cold germinators, keep the warm ones in the fridge.

snowdrops

Draba lasiocarpa (warm germinator)

Erinus alpinus (warm)

Papaver atlanticum ‘Flore-Pleno’ (direct sowing)

Polygala vulgaris (cold)

Potentilla porphyrantha (warm)

Helleborus foetidus (moist, warm/cold)

Mitella diphylla (cold)

Fridays Frits

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Do you wonder about your Fritillaria seeds/seedlings/young bulbs? Wonder no more.

With many thanks to a very impatient grower, we can have a look at Fritillaria recurva little bulbs. Also, at my germinating seeds of Fritillaria atropurpurea.

The one-year old bulbs were found at the bottom of the pot. Fritillaria seeds are adapted to wind dispersal (like many Liliaceae actually) and should be sown superficial; then, the growing seedlings will adjust the bulbs to their desired, proper depth.

Fritillaria recurva: seeds to one-year old bulbs

My stratified seeds of Fritillaria atropupurea on Jan. 1st are starting to germinate (1,5 months of cold/moist stratification). And, by the look of the embryos, Fritillaria affinis will follow shortly.

As I already mentioned,  I’m not much of a Frits grower. I’ve grown a couple of species (non-flowering yet) and only this season I have sown more. By the way it goes, it is best to grow the bulbs in the same pot for two years; if necessary transplant the whole content of the sowing pot in a bigger one, keeping the bulbs at the same depth.

Fritillaria atropurpurea germinating seeds after 1,5 months cold/moist stratification (fridge)

If you have pictures related with the Frits species seeds purchased, please don’t hesitate to share!

 

Spetlem: Lewisia rediviva

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The bitteroot seeds I sown a month ago have sprouted. I looked at the little seedlings and thought about their story; the story of spetlem, from a time when the species wasn’t even yet described!

Lewisia rediviva seedlings; seeds sown January 4th, kept at room temp. for +/- 10 days, then in the garage (+/- 5C). I was planning to put the sowings outdoors but there was no snow for a while…The germination pattern can vary depending on the collection site (origin for these seeds: Butte Co., California)

An excerpt from an article recounting the discovery of the species during the Lewis and Clark expedition, available here: http://www.lewis-clark.org/article/311.
“An old Flathead Indian woman sat weeping on the bank of the In-schu-te-schu, or Red Willow River, in the shadow of the Chi-quil-quil-kane, or Red Mountains, singing a death song for her starving children. The rising sun heard her plaint, and sent a red spirit-bird to comfort her. The bird promised that from each of her falling tears a new flower would grow, tinted with the rose of his feathers and the white of her hair, and springing from a root as bitter as her sorrow but as nourishing as her love. The prophecy came true, and her people called the plant spetlem -“bitter”.”

Lewisia rediviva in flower; with many thanks to the provider of the picture.

How the bitteroot came to be collected during the Lewis and Clark expedition(1804/06), how it was named and by whom, and more importantly how profound this little species was intertwined with Indigenous Peoples  lives – I hope you will read about it all in the article provided. It is a great story, especially for a cold, snowy day!

Advice for growing it, and more beautiful pictures, in this thread from SRGC forum: http://www.srgc.net/forum/index.php?topic=15817.0

 

Results on Rubus chamaemorus germination – update 2 and 3

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For those who didn’t follow the story from the beginning, please see these links:
Homework for today: Rubus chamaemorus germination – December, 2019
Preliminary results on Rubus chamaemorus germination – update 1 (Jan. 10, 2020)

Lot#2 has been eliminated (the seeds were damaged during the endocarp removal).

Lot#1 – the first signs of germination appeared pretty fast, with the radicle emerging first, in most cases.
A few seeds were also discarded, but almost all the remaining ones showed signs of germination (radicle growth and greening of cotyledons).
The container/and the pot with transplanted germinated seeds have been kept under light at +/- 20C.

Rubus chamaemorus seeds starting to germinate, Jan 19

Rubus chamaemorus germinated seed

The main aim of the experiment was to see if the seeds indeed germinate at warm/room temperature, and they do.
But excising the seeds from the pyrenes is not an easy job and many will get damaged during the process. Especially for large lots of fruits, it is a completely unpractical method.

Rubus chamaemorus pyrenes: hwt x 3 times, placed at warm/light

Another attempt is being made by using a hot water treatment (hwt) on the pyrenes. The hot water treatment gave excellent results last year for replacing the mechanical scarification usually employed for Fabaceae seeds.

Lot#3 was treated with boiling water 3 times, one day after another starting on Jan. 16, and then placed in the same conditions like lot#2. We’ll see if the treatment was enough to produce fissures in the endocarps and allow germination without extracting the seeds.
Update will follow.

 

Recap:
If Rubus chamaemorus fruits are sowed, they require 270 days of cold/moist stratification in order for the endocarp to broke down and allow the seeds to germinate. Translation: for fruits sowing in late fall, expect some germination in the third spring after sowing.

If you manage to remove the endocarps without damaging the seeds, they will germinate quite fast at warm (room temp.)/light.

 

Update 3 – regarding germination trials out (2021):

First, because I had a question about it: what went wrong with excising the seeds from within the pyrenes?
The problem was that using a very sharp scalpel, the seeds were damaged while cutting through the pericarp. Microscopic cuts or punctures led to the damage of the seeds and embryos.

Unless one is a surgeon, I don’t see it as a feasible method, even if the few unharmed seeds did try to germinate.

So, in early spring of 2021 I went back to a classical method of scarification used by plant nurseries for this type of ‘seeds’ by using  sulphuric acid. This is not something that can be applied at home and I don’t know if it is much in use in the nurseries nowadays; out of curiosity I had to give it a try.

One lot of seeds was treated with sulphuric acid for 45 min and another one for 1 h.

Rubus chamaemorus pyrenes – H2SO4 treatment in April 2021, kept in Petri dish on moist towel; picture taken Sept. 12/2021

Afterwards, the ‘seeds’ were kept under lights at room temperature, and… nothing happened. Some seeds seem a bit enlarged but obviously the time wasn’t enough for the endocarp to be eroded enough in order to allow water imbibition.
Later on I found one study suggesting a 3h treatment with sulphuric acid; maybe I will try it this coming winter.

 

Also, another more friendly method, like nicking, was also tried with no success.
Then I left a sample of pyrenes sitting in water since March! I thought that some may give in and imbibe but it didn’t happen.

 

Rubus chamaemorus pyrenes – after receiving hot water treatment x 3 times in spring 2021, then kept in water (regularly changed); picture taken Sept.12/2021

Conclusion: for home gardeners sowing as usual and patience may provide the best outcome in regards to germination of this species. Repeated cycles of warm/cold/warm/cold are necessary for the endocarp to broke down and allow water imbibition of the seeds and start the germination process.

Blue-eyes Wednesday

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The June garden review (in progress) it is a good occasion to update the info on Sisyrinchium mucronatum (Slender blue-eyed grass).
Seeds offered as S. montanum for a couple of years were probably a mixture of both species (please see the note on the S. montanum page).

When the light blue, delicate flowers start swaying atop of the grassy leaved tight clump in June, I always wonder why we don’t cultivate more the blue-eyed grass species.
Besides their beauty, all are super cold hardy, pollinator friendly, not requiring a lot of space and good companions to other native and non-native species.
Close to S. mucronatum I grow Primula mistassinica, Parnasia glauca, Viola nephrophylla; last summer were added young plants of Zigadenus elegans and  Prenanthes racemosa. Any other species preferring a slightly moist location (even temporarily flooded) in full sun to part-shade, would be good companions.

Sisyrinchium mucronatum (Slender blue-eyed grass) flowering in June

Preliminary results on Rubus chamaemorus germination – update 1

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January 10, 2020
The first post on R. chamaemorus (December 2019): HERE

First, a simple, short presentation of the Rubus fruit so that we understand the photos. The fruit is an aggregate of drupes. Each drupe presents a fleshy part (intended as a reward for dispersers) and a ‘pyrene’ in which the seed is protected by the hard fruit endocarp similar to the peach stone. Inside the pyrene, there is a seed covered by a thin seedcoat.
The embryo in Rubus species is fully formed, showing a small radicle and two large cotyledons.

Rubus chamaemorus pyrene

The endocarp of the pyrene is very hard, reason for the difficulties in germinating the seeds.
We shall see how to remove it in a simple way and determine if the seeds germinate at warm or need a cold period, to clarify the contradictory existent sources. I realize now that this may be due to the fact that some people tried to germinate the pyrenes while others tried the actual seeds!
When sowing the pyrenes, 270 days of cold/moist stratification are said to be required for germination, meaning 2 years (Baskin & Baskin).

Two lots of pyrenes were used.
Lot#1 was soaked in water since Dec. 18, with the water changed once in a while.
Lot#2 was soaked and also treated with hot water twice at interval of one week (see the ‘hot water treatment’ post).

I sectioned the first few pyrenes last week just to see how it goes, but the germination experiment was started only two days ago; that means about 3 weeks of soaking in water.

The endocarps were removed with a scalpel under a magnifying lamp. The easy way to remove them is by making a small section on the curved side of the pyrene, towards the rounded end. This way you avoid damaging the embryo radicle, which is at the opposite end.

 Rubus chamaemorus; pyrenes showing where to section to remove the endocarp

Despite the recommendation of the article presented in the first post, I find no need for nicking the seedcoat, which is very thin and sometimes even slides out easily (especially in lot #2).

Findings: the pyrenes treated with hot water were definitely easier to cut than the ones only soaked in water. For lot# 2 some of the seeds were already soft, a sign that the soaking time was too long. It is clear that the hot water treatment is very effective, leading to fine fissures in the endocarp. The soaking time should be reduced a bit, maybe at two weeks.

After removing the endocarps, the seeds were placed right away in containers (with lids) prepared with a layer of moist vermiculite and a coffee filter on top; this will allow for easy observation. I borrowed the idea from a friend who used it for stratification of seeds in the fridge.

The seeds (some still with half of the endocarp) and the embryos are sitting on top of the coffee filter, which can be easily replaced in case some of them develop mold (quite possible)

Considering the aspect of lot#2 of pyrenes and seeds, I wonder if the hot water treatment (done a bit differently) may not be enough to allow the seeds to germinate (?). I still have a small lot of pyrenes and will start one more treatment right away.
Removing the endocarps is not a practical solution for large scale sowing, plus other Rubus species (all with hard endocarps) have very small pyrenes.

So, until the next update – let’s have the kettle going!

Special thanks: to Trond Hoy for providing the bakeapple seeds and to Keith Baldie for sharing with me his method of stratification.