Typically Hosta plants are multiplied by splitting the whole plant into more, smaller plants, but you can grow Hostas from seed.
It’s about this time of year when enthusiastic Hosta growers are asking about information on how to grow Hostas from seed. It is now that the flowers of the Hostas are starting to go to seed and customers want to know how they collect it, what they can do with the seed, and what’s the best way to sow the seed.
Before you start, here is a bit of useful information….
Hostas are almost unique in the world of germination. Whereas most plants once pollinated, will produce seed with a part of the features of both the male and female parents. This means that the seedling will resemble their parents. With Hostas, this does not happen. They will not be like their parents. If you want the Hostas to be just like the parent then you need to vegetatively reproduce them. You need to split them, so all parts are identical.
Some Hostas are sterile (able to produce viable seeds). Some don’t even produce any seed.
In nature, the bees and insects will pollinate your Hostas for you. The alternative, is to cross-pollinate them yourself. This is a separate blog in itself, as it can be complicated and mind-blowing, at the same time. I promise, we will get to that.
Let’s assume our insects have done their job. The flowers will be pollinated and start to lose their colour and produce green pods where the flowers used to be. Left to their own device, these would ripen to a brown colour, in most cases, but there is the odd exception. These would then dry and crack open, dispersing their seeds to the ground. Germination will be sporadic or at best be subject to the winter weather. So why not try and collect your own
seed. This is the easy bit.
Collecting Your Seed. (it’s cheap and it’s free)
It will be quite clear when the flower has been pollinated, as it will form leathery capsules or pods, which will be green, initially. Inside these, will be the seeds.
When the seeds present in the capsule are black or dark brown, you can start harvesting them. Green pods or green seeds are not ripe and will not germinate.
Save the opened capsules and store them in a dry and warm place. Let them dry for several days. Then collect the seeds and store in a dry, dark place until they will be sowed.
Hosta seeds only keep their viability (the chance to germinate) for a very short time, so sow them as soon as you can after collection, once dried.
You can store the seed until spring, even at room temperature, but the viability of the seed is drastically reduced.
Sowing Method One - Outdoors
Using modular trays, small pots or even half trays, filled with your choice of compost. Small pots and modules make controlling the Hosta seedling much easier when the germinate.
Sow the seeds quite thickly, as Hostas are known to have a low germination rate.
Water from below and don’t forget to label if the parentage is known, and always make a note of the date of sowing.
Place the sowings into the garden, under a shelter or in any other area protected from rain and do not water it until spring. In the spring, when the danger of frost has gone by, place the pots into an open area and start watering them. It is best to cover them with some transparent cover to keep high and sustainable moisture and air humidity.
The seeds begin to germinate in May. In the middle of July, the seedlings should already be large enough to be placed individually into small pots. Remove any blooms in the first year to keep the plant healthy and from trying to go to seed again. The second year, the young plants are already strong enough to make flowers and bloom.
You can, of course, sow them directly into the garden soil in October or November having prepared the soil very carefully as seeds are fine and small.
Sowing Method Two - Indoors
Sowing indoor during the winter is more difficult to care for. First, you need a suitable indoor space, where the temperature is around ±20 °C, where you will have enough space to care for plants. You should be able to manage lighting, watering and other factors. So, this type of cultivation is more expensive and often requires some investment.
Put good draining compost into suitable pots, for example with a diameter of 10-20 cm. Slightly moisten the soil before sowing.
The time suitable for sowing is from December. Sowing seeds in January or February is also appropriate, but lower germination rates.
Sow the seeds on the surface of the compost. You can cover them with a little bit of sieved compost or just put on a bit fine water-absorbent material on the surface.
Hostas germinate in between 7 & 20 days, depending on indoor temperature and humidity. They do not need light to germinate. The germination temperature should be a bit higher, about 24-25 °C. It is advantageous to cover the pots with a plastic cup to increase the humidity. Spray the soil surface at least once a day with water to keep the soil surface moist. If the soil dries out, the seeds will not germinate! However, be careful, the soil should be moist, not wet.
Reduce the temperature to about 22c. once germination starts. You can then Once the seedlings have reached about 2cm, you can remove the plastic pots. This won’t all happen at once. Germination can be erratic.
However ..... Now The Work Begins
Once germinated, your seedlings will require overhead LED illumination. Check with the market to see what is available. There is plenty on the market to choose from.
Once your seedlings have reached about 3-4cm, you should be able pot them up into separate pots.
You should also be able to see some of the good traits and not so good traits of your germination. It can take 3-4 years to be sure of what to keep, but you do need to reduce numbers before potting up.
This is the hard bit to do. Remember when I said that the seedling would not be like their parents, what I really mean is that most of your seedlings will be green and boring and it’s time to cull. There literally could be thousands that all look the same.
Do not wait for 3 years to sort them out. Be ruthless. Cull all of those that really don’t come up to scratch. Be a little careful though, that little weak green Hosta may just wait several years to show how good and how different it can be. This is fine if you have the space. If not, you do need to be ruthless.
You may have thousands of germinated seedlings but be lucky to find just one, after several culls, that is worth saving. That is always a joy.
The beauty of growing Hostas from seed is that whatever you decide to keep, you have grown these wonderful creations from the very start, and you should be proud of what you have achieved, whatever you may have left.
…. and you can do it all again next year.
All that needs to be done now is to harden them off before planting out or potting on.
There are many Hosta growers that grow from seed, but generally, they cross-pollinate specific varieties with specific traits, in the hope that they can produce a ‘new’ variety, not seen on the market today.
These are specialist growers and have all the set-ups and equipment to be good at it.
Why not give it a go. See how you get on with sowing Hostas. You never know, you might even think it's worth doing again.
To learn more about Hostas, you may interested in reading : Grow and Maintain Hostas In Containers, Benefits of Companion Plants, What Are the Common Mistakes to Avoid When Growing Hostas?, Ways to Protect Your Hostas from Slugs and Snails and "Uncovering the Advantages of Bare Root Hostas:
Shop for Hostas HERE
John Plant
Rewela Hostas
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