Practical considerations for sowing in late fall and winter

For those who don’t know it yet…the devil is in the details, sometimes.

Sowing in late fall – early winter: what is different than fall sowing?
Most important is to consider that seeds must enter the cold cycle well imbibed with water. When sowing in late fall when temperatures are still well above freezing, this is not a problem. By the time the cold arrives (meaning temperatures around 0C and below), the seeds have already soaked a lot of water and will enter the cold stratification well prepared.

But when sowing in late fall (November) and advancing into the winter, even if the pots are well watered, the seeds may not be able to absorb the water fast enough when they are placed right away outdoors.
For this reason it is best to keep the new pots with sowings indoors for about 2-3 (4)weeks, and move them outdoors in the cold after that. It can also happen that some seeds will germinate, even when known to be cold germinators!

The same concept applies if you want to start the cold/moist stratification in the fridge.
Place the seeds in the moist medium of your choice (vermiculite, sand or wet towels) and keep them at room temperature first for a few days, before placing them in the fridge. You will be surprised by the change most seeds will undergo while absorbing water in only a few days.

I can exemplify with Fritillaria and Tulipa seeds that I plan to grow under lights indoors this year (2020). In this purpose I kept them at room temp. for about a week before placing them in the fridge; in some cases the embryos are already visible (hover the mouse for names).

Tulipa tschimganica seeds

Fritillaria latifolia seeds

Talking about stratifying seeds in the fridge, please consider first what species you want to germinate. Most of them germinate best when sowed and placed outdoors for the winter.
In the case of species known to require low temperatures for dormancy breaking (like various Gentiana, Saxifraga, most Ranunculaceae), stratification in the fridge at +/-4C is not a good option (unless you have a fridge dedicated to seeds and can vary the temp.).

True that in case of a mild winter seeds may not germinate in the first spring, even if sowed outdoors! Breaking the dormancy requires temperatures below zero for various periods of time, and if specific cold period requirements are not satisfied in the first winter, the seeds will need an additional cold cycle to germinate. In this latter case, keep your pots and take care of them until the second spring.

Talking moist packed seeds: a reminder that these seeds are in full development by late fall (their warm cycle completed and the cold one started), and in some cases there may be signs that the radicles are just about to emerge (classic examples: Asarum canadense, Trillium grandiflorum…).
The moist packed seeds require a cold cycle for breaking the shoots dormancy at this point, so they should be sown asap and placed outdoors. The best option is to use a cold frame, a cold garage, or in absence of these options bundle the pots together and fingers crossed for snow (alternatively, cover the pots with a thermal fleece, tarps, in case it gets very cold with no snow cover).

To finish about spring Corydalis

Before the year’s end, here’s a bit more about Corydalis solida and the likes (other tuberous species).
This is probably a repeat of what I have previously mentioned, but it is good to recap.

Corydalis solida and the likes (C. caucasica, C. cava, C. malkensis…) are promiscuous species, cross-pollinating freely, which means that growing them from seeds, there is no guarantee you will obtain the same form as the mother plant. But precisely in this ‘flaw’ I find their beauty because interesting forms can appear naturally; all one has to do is pay attention and select them.

A beautiful form of Corydalis caucasica ex. ‘Alba’.

Corydalis caucasica ex. ‘Alba’

Two other C. solida seedlings I am ‘watching’: a deep red one and a red with pink lips (most likely a cross from ‘Beth Evans’).

C. solida seedling1

C. solida seedling2

Nothing is easier than growing this type of Corydalis from seeds. The seeds are ready toward the end of May, and if you want to actively increase your stock, it is best to collect them; otherwise, the ants will carry them maybe in places where not all the seeds can germinate.

Fresh sown seeds will promptly germinate in the following spring (after a warm/cold cycle), grow for few months and then go dormant. My method is now to grow them in the same pot for 2 years and at the end of the second cycle to plant the small tubers in the ground (June/July).
In most cases, the first flowers will appear in the third year.

Corydalis solida- 1 and 2 years seedlings

Corydalis young tubers

Corydalis solida old tubers

Older tubers can be dug up and moved in the summer after the plants have gone dormant; part-shaded locations which do not dry completely in the summer are best.

Happy Corydalis growing!

 

Aconitum germination revised: 2019

,

It may become a tradition to publish revised notes on Aconitum germination around Christmas time every year; it only depends if new species will be available for trial-outs! My thanks to those making this study possible. Read HERE the starting notes on Aconitum germination.

Again, Aconitum comprises many species which are (in general) difficulty to germinate if the seeds were stored dry, some even after short periods of dry storing. But some species are more recalcitrant than others, and that’s what this study tries to looks at, including the effect of GA3 on improving the germination.

These are the main germination tables revised, Dec. 2019

The conclusion from last winter sowings is that Aconitum moldavicum and Aconitum hemsleyanum are difficult to germinate species even after a relatively short period of storing the seeds dry. It remains to be seen if some of the seeds will germinate in the second spring after sowing.

Aconitum kusnezoffii seedlings

Aconitum krylowii seedlings

Aconitum kirinense seedlings (2)

Aconitum kusnezoffii seedlings (2)

From the recently sown species there are moist packed seeds to share of Aconitum japonicum

Hepatica acutiloba pastel mix – seeds are starting to germinate! Together with the Aconitum they can be ordered via – Fast shipping option.

Shipping will resume after Dec. 26

Merry Christmas to all!

Homework for today: Rubus chamaemorus germination

,

Recently I exchanged few words about the Rubus chamaemorus (bakeapple) with someone who purchased seeds. While reading again a short but quite explicit article on the subject, I thought it would be good to do a little experiment of my own.
Although it needs a specialized habitat to grow well, R. chamaemorus is a desirable species; unfortunately difficult to germinate due to the very hard endocarp (the ‘seeds’ are actually pyrenes ;).

Today I had to pack seeds again and it was the perfect occasion: I counted two lots of pyrenes for the experiment. I intend to soak one lot as usual in water and for the other one I’ll use the ‘hot water’ treatment to see if it makes it easier to remove the endocarp.

I will update this post along the experiment, but until then anyone interested can do  a bit of homework:

GERMINATION STUDIES OF BAKEAPPLE (CLOUDBERRY) SEEDS – cjps79-010

Other studies also suggests removing of the endocarp to obtain germination but there are contradictory reports about the germination temperature.

 

 

Kernera and a trick for sowing fine seeds

,

 

Few species with small size seeds

Talking alpines species which usually have fine seeds, I will show a trick for sowing.
As everyone knows, fine seeds require light for germination and they need to be covered lightly; perlite is a good material choice, easy to find at almost any garden centre. Another good option it is to use vermiculite.
But not only I cover the seeds with perlite or vermiculite, I also lay a fine perlite layer on top of the sowing mix and water it lightly before spreading the seeds; this way the seeds will stick to the perlite and not get drawn deep into the mix ;) You can also use vermiculite in the same way.
I would say this is very important for warm germinators. For cold germinators, which will receive their cold/moist stratification outdoors, the light requirement is often replaced by the cold treatment, so you can use regular sowing mix for covering.

Saxifraga corymbosa seeds sowing

Light sensitive seeds sowing

Especially when placed outdoors for cold/moist stratification it is good to enclose the pots in a plastic bag/Ziploc/or plastic boxes. The small seeds are easily displaced because of the superficial mix covering and starting spring with the raise in temperatures, they can also dry out very fast; even a short period of dryness can be fatal if it happens at the exact moment of the germination start.

About Kernera saxatilis, or to use the common French name which is very suggestive: Kernéra des rochers.

This lovely rock garden species offered in the seeds-gift is hailing from mountain ranges of Southern and Central Europe. Generally it is overlooked by many and I feel I should promote it more.

You can find a nook for this delicate species in any rockery, big or small, trough, containers or any other planting holders. The small white flowers will appear on an elongated flower stems in the spring, and will be followed by ornamental beads-like fruits.

Kernera saxatilis flowers

Kernera saxatilis garden

Kernera saxatilis fruits

Kernera saxatilis seeds

It gets even better because the leaves rosettes remain evergreen, a most desirable trait in any cold climate – pictured here in November 30th.

Kernera saxatilis leaves rosettes end of November; these are still young plants which will increase in size over the years.

Did I mention that this is a very easy to germinate and grow plant?

 

 

 

 

 

 

Pink

,

Frilly pink with the long gone fragrance of June summer days – sounds about right for Wednesday.
Have a great one everyone!

 

 

Colors for a white week: Acinos

, ,

It seems that we will have a white week. But it is so easy to make it flower-colorful!
Since Acinos alpinus seeds were packed for few last orders I thought “A” + purple would be perfect for Monday; plus, we can feel the high altitude summer sun!

Acinos alpinus (syn. Calamintha alpina) – an easy to grow species in a rock garden, edge of a flower border; sun and good drainage.

Acinos alpinus – go wild and combine it with any other color!

 

 

Gentiana for a rainy day

,

What else better for a grey November day than a Gentiana?

The Gentiana and allies category has been updated. Few species are out this year and one notable species has just been added. No gentiana lover would wanGentiana for a rainy dayt to miss Gentiana uniflora, the Far Eastern counterpart of Gentiana verna (in the top featured image).

But all other Gentiana species are worth growing: Gentiana dahurica, G. septemfida collected in the garden or Gentiana asclepiadea, Gentiana lutea and G. punctata collected in the Alps this year, thank you!, not to mention their relative Swertia perennis. There are never enough Gentiana!

Gentiana dahurica

Gentiana septemfida var. lagodechiana

Gentiana lutea

Gentiana asclepiadea

Gentiana punctata

 

Magenta Thursday

For today: magenta with a red eye from Primula pulverulenta hybrid.  It was grown from seeds labeled P. pulverulenta but obviously a hybrid with P. japonica; it is meant to happen when the two are grown together. 

Primula pulverulenta hybrid with Athyrium ‘Ghost’ in the background

There is now a new category including all species from Fam. Primulaceae: Primula & allies
Small groupings of related species will make the search easier and will also speed up the inventory management.

Don’t miss the chance to grow Soldanella hungarica, Primula algida and P. auriculata – all wild collected seeds!
Androsace albana it is also not an easy to find species elsewhere.

Androsace albana

Soldanella hungarica

Primula mistassinica

Primula sieboldii pink

Primula amoena

Trientalis borealis

The heart

, ,

While preparing orders last couple of days, I stumbled upon a perfectly heart shaped seed among Fritillaria atropurpurea stock.
I took it as a sign that I must also sow few seeds and put aside a tiny package for myself, heart included :)

Fritillaria atropurpurea seeds

 

There is one last pck. left for Fritillaria atropurpurea. All other Frits sold out at the moment, thank you – merci

 

Reminder: this is the best time to start sowing species that require cold/moist stratification!!!

Surprise, surprise! Roscoea schneideriana

,

Plus, growing Roscoea from seeds

October ended with a nice surprise. Roscoea schneideriana has flowered beautifully this year and in all honesty I didn’t expect any seeds; it was enough to see it thriving in the garden. Then, one day I noticed that one capsule had burst open and the seeds spilled on the ground.

Roscoea schneideriana with split capsule and seeds in late October

It is always very rewarding when a plant started from seeds reaches the point of flowering well and produces seeds! And Roscoea schneideriana is a special one, with characters a bit unique in its genus (to mention just the leaves arrangement, the length of the staminodes and the round anther appendages). It grows wild in Western China (Sichuan and Yunnan), in mixed forests, open limestone slopes, among rocks and ledges of mountains between 2600-3350 m alt. (from The Genus Roscoea, Jill Cowley).

Roscoea schneideriana flowering in early September; notice the round anther appendages, a good ID character for this species

I know that most people in our climate avoid growing hardy gingers, but in fact they are not difficult to start from seeds and many species are cold hardy.

Most species are warm germinators, or will germinate after a short period of cold/moist stratification (1 month). So, you can sow and start them under lights indoors in February/March, or directly outdoors in April/May (depending on the region).

In the first year after sowing, the seedlings will grow only for a few months and then become dormant! For this reason, try to grow them well watering and applying a light fertilizer once in a while. Do not prick out the seedlings! If necessary you will transplant them in a larger pot after they become dormant.

When the leaves start yellowing, reduce the watering and try to not overwater the pots when they are complet dormant; only keep them slightly moist.
The seedlings should be grown in the same pot (the sowing pot) for 2(3) years at least until the little tubers can be handled more easily. 

As noticed, the seedlings form fleshy, elongated tubers (various forms depending on the species). They need a bit of extra attention for a couple of years (in most cases I overwinter them in pots in the garage). Again, transplanting of the tubers in bigger pots should be done only when dormant, in very late fall or better in early summer (Roscoea always they start growing very late in the season).
After approx. 3 years you can plant them in the garden (in a part-shaded, well drained location – this is very important) and you’re done!

Roscoea schneideriana seeds (2)

Roscoea scheideriana seedlings

Roscoea schneideriana tuber

Roscoea tibetica young tubers

Growing from seeds you always get to play with a few seedlings not just one plant. The advantage is that we can experiment with planting young plants in various locations in the hope to finding the best one.

Roscoea are much easier to establish in the garden when planting young (3 years old) tubers in the summer just before they start growing. During the season the tubers can lower themselves to the soil depth of their liking (which can be quite low) and thus survive better our harsh winters.

One more thing: don’t wait for them to emerge at spring time. They sit underground chit chatting with various Arisaemas and both forget it is time to show up. And then they all do it in a big hurry in mid-summer!

You can also read about R. auriculata below (Earth octopus). 

Beyond flowers II

,

Sanguinaria canadensis, our most beloved spring harbinger must be appreciated beyond its flowers; albeit beautiful, they last only few days. In very dry years, the leaves may go dormant early. However, with enough moisture they remain lovely until late fall!

Sanguinaria canadensis (bloodroot) pictured a few days ago

Asarum canadense it is also a ‘beyond flowers’ species; the flowers appear at the ground level and are barely noticeable. But the leaves emerge in early spring and throughout the season will keep very good company as a groundcover for other species, plus they remain decorative until late October.

Asarum canadense (wild ginger) leaves spotting the woodland floor in late October

Soon, only the queens of the woodlands (i.e. Hepatica) will be reigning over the forest, together with a few loyal evergreens (Chimaphila, various sedges and Mitchella repens). Their foliage will be replaced by the new leaves only in the spring after the flowering.

Asarum canadense and Hepatica acutiloba foliage in late October

Hepatica acutiloba pastel mix

You can grow these species together, like in their natural habitat (add few Trilliums and Erythronium americanum, Claytonia virginica…) or in various other combinations.

Sanguinaria canadensis spring

Asarum canadense spring

Hepatica acutiloba spring foliage

Appreciate them beyond the flowers, spring, summer and fall!