If you’ve ever started tomato or pepper seeds indoors then you’ve probably filled pots with soil, stuck the seeds in, kept the pots watered, and in a few days the seeds germinated and the little green leaves popped up. Cheap thrills, but it is thrilling and it is cheap and easy. Unfortunately most wild plants don’t work this easily.

Seeds of vegetable crops are typically easy to germinate because they’ve been artificially selected to be so. Any dormancy that the wild ancestors might have had has been removed - no special treatments are necessary to induce the seeds to germinate quickly and synchronously. This is of course important for farmers and gardeners, who certainly don’t want to have to deal with a seed that just sits there for weeks or months or that has to be coerced in some complicated manner.

Continuing to grow seedlings into plants is also relatively easy for vegetable crops. Most vegetable crop plants are annuals, and their above-ground shoot growth is rapid and vigorous.

Compare with wild perennial plants. Since they’re wild their seeds have to have dormancy - a condition that prohibits germination until the winter has passed or a certain period of time has passed. This is the phenomenon that we have to deal with in propagating native plants by seed.

The growth of perennials from seedlings is quite different from that of annuals and domesticated plants. Perennials have to establish a root system capable of storing enough energy to get it through the next winter. Consequently their shoots may just sit there doing nothing for weeks, belying the intensity of growth underground away from sight, while their annual cousins who don’t have to develop that root system are going gangbusters above ground.

I’ve written quite a bit about this, as well as about a few early versions of germination methods (see the sidebar under “tutorials”). So except for saying that I’ve been working to develop a fairly easy, consistently successful, and space-saving method of germinating seeds of a great many species, I’m going to skip the details of all the intervening non-successes.

Here’s the method that is giving remarkably good results. I am now germinating perennial (and annual) seeds in baggies. The initial steps are simple and have been described in the March tutorial. (#) indicates some notes at the bottom of the page.

Dump a few dozen seeds along with a tablespoon or two of moist fine soil (1) into a snack-size (6.5" x 3.25") baggie with a sealable top (the cheapest you can find). If you know the seeds to have no dormancy, just lay the baggie under the lights in a warm room until germination occurs. If you know them to have dormancy, just follow the directions.

For example, many seeds require 1-3 months of cold treatment (stratification), whereby dormancy is broken (2). I can fit dozens of these seed-soil/baggies into a small place in the fridge, much easier that trying to fit dozens of 4" pots. Other seeds (hollies, for instance) required 6 months warm treatment followed by another 6 months of cold; this is just as easily adaptable. If you don’t know what the treatment should be, just put the baggie under light for a few weeks in the warm, and if nothing happens then put the baggie in the cold for a couple of months.

I started stratifying seeds this way back in February, and have been removing and planting them since. One possible approach after removing a baggie with its ungerminated but ready seeds is to immediately remove small amounts of seed-soil mix and mix them with the top layer of soil in a pot or plug tray flat; in general I don’t recommend this except for the tiniest most delicate of seedlings and only if constant care is taken to keep the soil moist and the air above the pot or flat humid.

The way I prefer now is to just let the seeds germinate directly in the sealed bag. They look something like this:


These seedlings are ready to plant into soil (3). First you should know what a seedling looks like, and which parts are which.


The above seedling is a dicot, with two seed leaves or cotyledons. Monocots, such as grasses, will look somewhat different but the same rules apply. Look at the left side, the shoot part. The cotyledons are storage organs for the developing seedling, but they also do photosynthesis. They are not true leaves however, and will eventually wither and die. It’s important not to squash or damage the join between the stem (in a seedling the stem is called the hypocotyl) and the cotyledons because this contains the apical meristem from which the true leaves and the rest of the above-ground parts will emerge (4). Now follow the hypocotyl down to the transition zone. Below this is the root system; when you plant this seedling, the soil should come up to this zone and probably not much further - the hypocotyl should remain above-ground.

Here’s a couple of examples of planted seedlings:


I’ve planted these seedlings into 50-plug trays filled with a fine, pre-fertilized soil (5). The seedlings on the left were large and relatively tough. Their roots had grown together but I gently pulled them apart by hand and inserted them into a hole dug into a plug, then gently pushed the soil back into the hole, covering the root to the transition zone. For the next few days I’ll spritz these guys several times a day, and I’ll keep them under lights indoors until they harden. I will NOT put them out into the direct sun for quite some time.

The seedlings on the right are more difficult - there were many of them and they were very tiny. I used a pair of fine forceps to handle them, preferably by grabbing a lump of soil into which a half-dozen or so grew together, and then transferred the entire lump along with its seedlings to a crack in the soil top in the plug. I prefer not to touch the seedlings themselves, but it can be done if delicately. I gently press the soil around the little colony. Again, for the next few days I’ll spritz several times a day - I may even cover these tinier seedlings with light plastic if they seem to be stressed.

In both cases, try not to let the shoot system, stems or cotyledons, come in contact with the soil. Watch for fungus! If seedlings wither and die, even when moist, it’s called “damping off”, it’s caused by a fungus, and the humidity should be reduced.

Flats of seedlings should not be allowed to dry out for several weeks. Watering cans deliver water too forcefully to water from above. I put the entire flat into a tray and water from below until the soil in the flat is soaked, and then put back under light. Eventually though you will need to fertilize the seedlings as they develop - continued watering will wash out the fertilizer already in the soil and it will need to be replenished.

One alternative to this method that I’m playing around with is to leave the seedlings in the baggie for awhile and let them develop. After germination, it’s important to open the baggie to the air, but gradually 6. I unseal the baggie, and then hang it up under the lights with a clothespin. For the first couple of days I’ll let the clothespin pinch BOTH sides of the baggie opening, then I’ll hang it up by only one side, fulling exposing the seedlings to the air. At this point it’s important to keep the soil and seedlings moist (but not muddy!); I spritz into the bag a few times, once a day, and that seems to suffice. Eventually I predict the seedlings should be much larger and more easily planted, perhaps into 4" pots.

Now get out there and grab some mature seeds off a favorite plant and try it!

NOTES

1. Soil for germination should be fine; it should not be prefertilized. For some species, seeds will be inhibited by the ammonium that is usually a part of the fertilizer. The soil should be sterile (although note that some seeds, for orchids for instance, must have fungi present for germination and seedling development). The soil should be moist, but not muddy. It’s probably possible to use another medium, such as vermiculite. Peatmoss is probably too coarse and its acid qualities may inhibit some seeds.

2. Stratification must be done moist. It doesn’t work to put dry seeds into the fridge. Legume seeds often have hard coats that should be scarified, nicked or roughed up with sandpaper. Many very tiny seeds will require light to germinate, but needn’t be in light during the stratification period.

3. Soil for seedlings should be fine. It may be prefertilized or not, but if not keep in mind that fertilization will soon be necessary.

4. The seedling in the photo has already developed its true leaves, but for many other species this will not happen for some time. All you’ll see will be the cotyledons.

5. I prefer to use plug trays. These are standard trays with 50 small cells into which soil is placed. For most seedlings at this stage 4" pots are just too large. Once a good root system has developed in the plug trays, I’ll transplant into 4" pots.

6. Once seedlings have formed in the baggies, many species will begin releasing the gaseous plant hormone ethylene (remember ripening bananas by putting them in a bag with a cut apple?). If this hormone accumulates too much it may cause weird development of the growing seedling. Best to give it some air!