Warm Peonies

Instead of getting warmer the weather seems to go backwards. Good news is that in the cold frames things are definitely moving in the right direction.

I noticed the first little red shoots of Paeonia japonica on April 1^st. The seeds were sown last late summer: hypogeal germinators, forming roots during the warm period and the first shoots after the winter cold period (cold/moist stratification).

Paeonia japonica one year old seedlings with the first shoots peeking from the pot gravel, April 2018

This is the reason I recently recommended that seeds of Paeonia species (except Paeonia tenuifolia) to be bought and sown as warm germinators. The sowing can be done throughout summer (up to August in a cold climate).
If sown in late fall or winter nothing bad happens, just that it makes no sense to occupy the space with the pots since the seeds need a warm cycle first, plus in case of a wet winter the seeds may rot.

The summer-fall sowing is very straightforward, just use taller than usual pots, if possible: sow, water very well and protect the pots from the critters. Keep well watered and when the winter arrives, place the pots in a frost free location: cold frames, or ‘plant’ them in the ground.

Keep in mind that even if you don’t see anything there are (should be) roots inside the pots!
In this idea, keep an eye on the pots, not to receive excessive rainfall, especially when it gets very cold; this easily leads to roots rot.

Another sowing method is to provide the warm cycle required by keeping the seeds in moist vermiculite in a Ziploc bag (indoors at room temperature) until they form the roots and then place pot them up and place the pots in the fridge for 2-3 months for the cold period. This method requires more supervision; I did it once and now I think it is best to go with the natural cycles of warm and cold.

But if you purchase the seeds too late in the season or don’t have a cold frame, it is a doable method.

I am also thinking about a third method for those on cold climates who want/need to sow in October-November and don’t like to play with Ziploc bags: sow in pots as usual and keep them in the house until Dec./Jan. for the warm cycle (this would give the 2-3 months required), check gently to see if the roots have grown, then gradually place the pots outdoors under the snow (or in the fridge). Gradually means, first keep them for a while in a cold location (garage…); also keep in mind that we don’t usually have reliable snow cover.

I showed it with another occasion, and it is nothing new about it, but here’s what these peonies seeds are doing during the warm cycle,  no matter if sown in pots or kept in the Ziploc bags. We need to be aware at all times of the roots growing in pots that otherwise don’t show anything visible on top. If you let them dry out excessively or to freeze, of course no shoots will show up in the spring!

Paeonia rockii hybrid, emerging roots after a warm period provided in moist vermiculite; the roots will grow further, so best to use taller pots for sowing

As said in this older post The sleeping beauties, it is worth growing species peonies from seeds: they are beautiful, hard to find and when it happens to be available they are on the expensive side. Not all the seedlings may come true to species because of cross-pollination, but even the hybrids obtained from the species are special.