Welcome to the first quarterly newsletter for the Lilium Species Foundation. Yes, we are finally launching the newsletter, the next step in our plan to conserve the Lilium species in the wild and in cultivation, provide a source for Lilium species to gardeners and collectors worldwide, and provide a resource for learning about them.
The Lilium Species Foundation has its roots in the Lily Species Preservation Group in NALS, founded by lily expert Ed McCrae. His vision was to see the lily species grown and preserved, and made available to growers, breeders, and the general public. Eddie grew lily species at Lava nursery near Mt. Hood, in the native range of the Mt. Hood Lily, Lilium washingtonianum. Eddie was a strong advocate for preserving the species in the wild and also felt that conservation through cultivation was an important part of ensuring the continuation of these botanical treasures.
One of us, Bret Hansen, worked closely with Eddie back in the day and learned precious knowledge about how to cultivate some of the more difficult lilies. He has spread this knowledge through the Lilium Species Foundation's Facebook group and has also taken seed donations and distributed seed to growers. He's also spearheaded the effort to grow the species at the same site, Lava nursery, today, using seed saved in cold storage from Eddie's original operation, plus donated seeds from generous lily growers.
The other of us, Gordon Hogenson, is an enthusiastic lily grower living in Duvall, Washington. He has made it his mission to grow and propagate Lilium, and with seeds collected from many sources around the world, is growing over a 100 different species of lilies. Together we hope to provide a wide range of species for members and the general public in the coming years.
In this newsletter, we're publishing an article written by Gordon Hogenson on how to grow Lilium species from seed. Have you own tips for growing species lilies from seed? Or questions about the methods discussed? Let us know! Comment on this post online or send mail to gordonhogenson at yahoo.com (email address modified to prevent spam bots from using it directly).
Growing from seed
by Gordon Hogenson, March 13, 2020.
Growing Lilium species from seed is a rewarding hobby. There are many different species you can grow and many that are not that difficult, once you learn the right techniques. By growing from seed, you can grow many lilies that you would not be able to find otherwise. Your gardening friends will be excited at your results. Patience is rewarded in this hobby, because it does take a while to grow Lilium from seed. If you start with some of the faster-growing species, you can achieve blooms in the second or third year. Others will start to bloom in the following years. Caring for them well will speed things up.
First you need to know the different germination types. The two basic types are epigeal and hypogeal. These are Greek words: epigeal means “above the earth” and hypogeal means “below the earth.” The further refinements of germination types have to do with the timing of all this, relative to the seasons. Immediate if germination doesn’t require a cold season, or delayed, if it does. So, the four basic types are immediate epigeal, delayed epigeal, immediate hypogeal, and delayed hypogeal.
Epigeal lilium germinate and send up a green grass-like leaf (the seed leaf or cotyledon) in the first season of growth. Often, the seed itself is also lifted out of the soil by this leaf. After the cotyledon has been growing a while, true leaves start to emerge, which look less like grass and are shaped more like the leaves on a lily. If you’ve grown onions or lawn grass from seed, you may be familiar with this germination pattern. Like lilies, onions and grass are monocots, so they only form a single cotyledon leaf rather than a double cotyledon like dicots do.
Hypogeal lilium germinate and don’t produce a seed leaf, but instead the root and bulblet are produced first, and a leaf doesn’t emerge until later. The first leaf that does emerge is not a cotyledon, it’s a true leaf.
Most hypogeal species are delayed, so they require a cold season before green growth appears. The root and a small bulblet are produced in the first warm period, but the leaf doesn’t emerge above ground until after a cold period has occurred, so not until the spring after the first winter after the initial germination took place.
There are two basic types of delayed hypogeal germination: the normal type or “warm germinators.” They germinate well at room temperature. This type includes the martagon species, the species that form the basis of the “Oriental hybrids”: auratum, speciosum, japonicum, and rubellum, many European species such as bulbiferum, monadelphum and its kin, some Asian species like ciliatum, ledebourii and polyphyllum, and finally, the Eastern American species canadense, superbum, michiganense, and grayi.
The other type of delayed hypogeal germination is is “delayed hypogeal, cool germination” which is the germination type of the Western American species.
Delayed hypogeal germination
A few lilies, like dauricum, are usually immediate hypogeal germinators. That means they don’t wait for a cold season before sending up the first seed leaf. This is seen occasionally in martagon seedlings, some Oriental species and their hybrids, and some Western American species from southern areas, such as parryi, and humboldtii ocellatum.
Delayed epigeal germination
Another type is delayed epigeal germination. Whereas most epigeal species can be sown in the spring and will germinate that spring, delayed epigeal species need a cold period before germinating. Species with this germination type include the European species pyrenaicum, chalcedonicum, and pomponium.
When to sow
The rules for the timing of seed sowing can be summarized as follows.
Sow in spring: immediate epigeal, immediate hypogeal. If you’re used to starting vegetables from seed under lights in late winter or early spring, you can use similar procedures. Sowing in late winter indoors is fine. Germination can occur at room temperature or cooler. Some species, such the Chinese alpine species, prefer cooler temperatures for germination than others.
Sow in summer: delayed hypogeal (warm germinators). Sow seeds in mid-summer and hold until the following spring.
Sow in fall: delayed hypogeal (cool germinators). In the Northern Hemisphere, sow in October and keep cool throughout the winter, but avoid freezing. An unheated room such as a garage is probably a good environment for this. If you live on the West coast of North America, you can use an outbuilding.
If you sow at the wrong time, there’s no need to give up. The seed will do its thing when the right conditions occur, as long as they aren’t killed by extreme temperatures or excessive wet or dry. Just keep them in moderate temperatures and avoid drying out, and you should be fine.
Methods of sowing
There are three methods: sowing in pots, sowing in a plastic bag or glass jar with a moist, soilless medium such as vermiculite or perlite, or sowing outdoors in natural conditions.
Sowing in pots
You can sow seeds in any reasonable potting mix. Drainage and aeration are important, so avoid dense and airless media. I mix potting soil with perlite when starting seeds. This gives better drainage and better aeration.
Small pots (3.5”) work fine, but somewhat larger pots (4-5”) are better. Some growers use gallon-sized pots with a large amount of seed. I use small pots for the initial stages since this lets me grow more with a smaller amount of initial soil. In about a year or two, you will have to repot or plant outside, since lilies will outgrow those containers and also use up the soil.
Spacing of seeds in pots is typically about a half-inch or 1 cm. In my smallest pots, I put nine seeds. In slightly larger pots, I plant 4 x 4 or 16 seeds. I usually place each seed individually to ensure good spacing.
Cover seeds with ¼” to ½” of potting soil, and cover the surface with a ¼” or ½” of course material. Any course material is fine – course sand, granite grit, or small-grained pumice. Avoid limestone chips as these will lead to too alkaline conditions.
Water well in each pot. You might wish to add Gnatrol to the water to set up a colony of the Bt bacteria in the soil. Bt is a larvicide, which will prevent the fungus gnat larvae from feeding on your lily seedlings.
I generally put 18 of the small pots in a flat and cover securely with a clear plastic lid. This keeps the soil from drying out. Others use plastic bags or glass lids.
Store at the appropriate temperature, and out of direct light. Direct sunlight will cause overheating and kill the seedlings. Indirect light is OK for short time periods, but over time, light will lead to algae or moss growth. The best conditions for seedlings undergoing stratification (storing over a cold period) is in a closed cabinet. For immediate germinators, keep in indirect light.
For hypogeal germinators in stratification, start watching for shoots coming up in late winter, especially during warm periods. Move pots that have germination over to the growing environment (more about that later).
Plastic bag method
I enjoy the plastic bag method, because I can see what’s going on with the germination process. It also requires more from the grower during the winter months, so don’t use it if you would rather plant the seed and forget about it until spring. I would recommend it especially for delayed hypogeal species since it lets you see what’s germinated and once you have bulblets forming, you can easily put the bags in the refrigerator to give them the needed cold period.
The plastic bag method involves putting a small amount of medium in a ziplock bag, adding a small number of seeds (say 25 or less), and adding a small amount of water. The amount of water to add is just enough to moisten the vermiculite evenly, but not so much that you can see excess water collecting at the bottom of the bag.
The medium I use is vermiculite. I recommend it if it's available, since the brownish color lets you see the white lily bulbs apart from it. You can also use perlite, but the white color will make it more difficult to see the bulblets. I have used both course and finer vermiculite, with good results.
Once started, label the plastic bag with the species and any identification numbers, as well as the date you started the process. That will be important later, as you might keep the bags for a long time. If you don’t already know the germination type for each species by heart, you might write down the germination type (DH for delayed hypogeal, etc.) since that will help you manage the seeds.
Regardless of the germination type, it helps to put all freshly prepared plastic bags in a warm environment, such as under grow lights, for a few days or up to a week. This lets the seed imbibe moisture and kick-starts the germination process. After this, move the bags away from the warmth and into the appropriate temperature for germination.
You should check the seeds every week or so, and open the bags to allow for an exchange of air. Watch for mold. I remove any moldy seeds promptly. These are dead seeds that wouldn’t germinate anyway. If a batch of seed is particularly prone to mold, add a small amount of powdered fungicide, such as some copper-based products.
Shaking up the bags is OK when the seeds haven’t yet germinated, but once germination occurs, handle gently to avoid breaking the delicate roots.
For most delayed hypogeal species, start the process in mid-summer, maybe July and August are the main months for this. Keep the bags protected from direct light and store at room temperature. Within a few weeks, or maybe more, germination for delayed hypogeal seeds occurs and you can see the bulblets begin to form. After most of the seed has germinated and formed bulblets, you can move the bag into the fridge to experience the cold period. If you are using a domestic fridge, avoid storing a large number of apples in the same fridge, since apples release ethylene gas as they ripen. Ethylene interferes with bulblet growth, so is best avoided. You can also leave it at room temperature for a time, and move it to colder temperatures later.
For Western American species, start the seed in the plastic bags in the fall. In the Northern Hemisphere, in my area near Seattle, October is good. Keep at cool temperatures, but not in the fridge. An unheated room, such as a garage, is fine. If you live in the Western American states, outdoor temperatures should be fine with some protection such as a cabinet or building, and you might consider moving them indoors if unusually cold freezes are expected.
Once you’ve given two or more months cold treatment, remove from the cold. You can then plant the germinated bulblets in small pots, and they should grow and emerge above the soil. I usually wait for the green shoots to appear in the bags and then pot up just the seedlings that have formed green shoots, taking care to ensure that the green shoot is pointing up and is emerging a little above the soil, but this is considered too fussy for most growers. Be careful when potting up germinated seedlings. They are very small and fragile, and the roots might be tangled up with each other. Most will still have a seed husk that you can use as a handle to pick them up. If the roots are tangled up, you can gently separate them by pulling alternately on one or the other.
I would take care to prevent the seedlings from drying out during the potting process. Avoid doing this work near a heater that blows dry air over the seedlings, avoid harsh sunlight, and complete your work on any one bag in one sitting. I usually do this work in the morning in a cool, sunny room. You want enough light to see what you’re doing, but not too much to be potentially damaging to the delicate roots.
I would pot anywhere from one to nine bulblets in a pot, preferably three to five. You want the root to be stretched out, not bunched up. Filling the pot partway, and tilting it on its side so you can lay the roots down and then bury them is a good technique. Once you have them placed in pots in the soil, water everything in. If you have problems with fungus gnats in your potting soil, add Gnatrol or Mosquito Bits to the water before watering in these lilies. I use Gnatrol, but I have heard about Mosquito Bits, which is similar and possibly less expensive.
You can also use this method for the delayed epigeal species. In that case, start in the dead of winter, giving the seed the initial few days in warm conditions while they imbibe water, and then keep seeds cool, such as in the refrigerator, for at least a month. As you check the seed, watch for germination. As delayed epigeal seeds germinate, they start with a small root and then the root curls back on itself and a green growing shoot begins to form. I find it best to pot up once the doubling-back has begun to occur. Pot up too soon and you might not see them ever emerge above the soil.
At the point where seeds are potted up and watered in, I give about a day to settle before putting them under the lights. This lets the bulblets and roots adapt to being in the soil before being put under the heat of the lights.
Regardless of the germination type, once you get to the point of a lily seedling in a pot, the process is much the same regardless of species.
I recommend using artificial lighting, such as using T5 LEDs or fluorescent tubes. The grow area may be at room temperature, but if you’re doing this in the house, avoid areas that receive a lot of direct sunlight. Best is slightly cooler than the typical house, either an unheated room in winter, or a garage that stays cool.
If you have a very sunny room or greenhouse, that might work, but avoid overheating. Room temperature or below is best. Success outdoors is likely to be much less, but if you don't have another option, try using a cold frame to protect against the elements, and protect from slugs, snails, mice, as well as larger animals and children.
The amount of light required is less than for vegetables such as tomatoes and peppers. Give them artificial lighting such as from fluorescent grow lights, but avoid putting the plants too close to the heat from the lights. Regular shop lights are not as good as lights intended for growing plants. T-5s are better than the older T-12s. The best are LED lights, which you can usually use in T-5 fixtures.
If lilies are growing spindly, give more light or move the lights closer. If they are crisping up or drying out too fast, reduce heat or increase distance from the light.
Watering seedling pots
Check seedling pots daily or every other day and water those that are starting to dry out. Once plants are more established, you don’t need to check them daily.
If you have fungus gnats, add Gnatrol to the water, and hang yellow sticky tape (fly paper) near your grow area. Or maybe try getting a butterwort, a carnivorous plant that has a voracious appetite for fungus gnats. If you do, let us know how effective it is.
Watering can become tedious. Watering from below can be a time-saver. Ideally, small pots are in flats that have solid bottoms, so you can add water to the flat and water all the pots easily. Be careful not to allow the pots to sit in water for very long.
You might experiment with capillary mats and drip irrigation lines for times when you aren’t around. I have heard about using unglazed clay pots without drainage holes in combination with a capillary mat, but haven't tried it yet. If you try this, let us know how it works out.
Larger-scale production should involve some type of automatic watering system.
Fertilizing seedling pots
You can also add a bit of liquid plant food to the water once a month or so, at half the recommended strength. Some potting soils contain enough nutrition to keep lilies from starving to death, but plant food will assist growth. Too much fertilizer is unnecessary and could be damaging.
What to expect
Some lilies are more vigorous than others. Some are very slow-growing, or at least start slowly. The slow-growing lilies will only generate a single leaf in the first entire year. The following year, multiple leaves will be produced in a basal cluster. Other lilies form a basal cluster of leaves right away.
The next stage of growth is the stem. The first stems are not flowing stems, but rather short stalks with leaves that terminate in a leaf or leaves without any buds.
Finally, in a spring when the first flowering will occur, a more substantial stalk emerges with a few buds. The year after that, the plant is considered mature and will produce a more substantial and typical adult flowering head.
Some growers recommend planting the seedlings outdoors in the spring of the first year. For many gardeners, this doesn’t work that well, because in the outdoors, there are too many uncontrolled factors that could kill your lilies. Small seedlings are apt to fall victim to any number of threats outdoors, such as bad weather, slugs, or rodents. If you have the ability to keep the seedling pots from overheating or drying out through the first summer, and you can store them over winter in a place that’s protected from rain and excessive temperature swings, then planting the following spring will give them that much greater a chance to survive.
You can also pot up the small seedling pots into larger pots (a gallon or so) and keep your lilies in containers. I watch the bottoms of the pots to see if roots are emerging from the drainage holes, or watch for stems. Generally, lilies that are producing stems are mature enough to need a gallon-sized pot.
When potting up, I pot the entire seedling pot, with multiple individual seedling bulbs, into a larger pot. This gives the typical seedling pot plenty of additional growing space and soil.
Good luck! Growing lilies from seed is a fun rewarding hobby, and will let you grow a much wider range of lilies than you (or your friends) knew existed.