How to Grow Bamboo from Seed
Most species of bamboo only produce seed about once in a long human lifetime. And most species produce seed all over the world within the span of a few years. Therefore, you may only have one or two opportunities to plant any particular species of bamboo and it will be worth going a little overboard trying to get it right. If you get a chance, here are steps to get the most out of any bamboo seeds you acquire.
1 Buy or make a mini-greenhouse with peat pellets as the planting medium. "Jiffy" makes one that holds 72 pellets and costs about $5 US. Nurseries or garden supply stores may have other options too.
2 Put a layer of pellets into a flat bottomed cake pan. Bring a pot of water to a boil and pour the water slowly over them to expand them. Boiling water not only works better to expanding them, but will have some sterilization value to lessen the rate of seedling failure. Repeat this step until you have all the pellets you need ready.
3 Put the pellets back into the mini-greenhouse. Depending on how wet they got, you may need to leave the top off for a couple of days to let them dry out a little. Sogginess is not good, and the pellets hold water really well. The ideal is for the pellets to be damp, but not wet.
4 Soak your seeds in about 85° F (30° C) water for 24 hours. Make sure it doesn’t get too hot, as temperatures over 105° F (40° C) can kill your seeds. Cooler temperatures however, will not hurt the seeds, but may delay germination by a few days.
5 Use a skewer or chopstick to open and rough up the top part of the peat pellets.
6 Put only one seed in the middle of each pellet. Because bamboo seeds are rare and expensive, you don't want to risk having two sprout in the same pellet and have to lose one of them.
7 Add a small amount of “seedling mix" type potting soil over the top of your seeds. 1/8 to ¼ inch (2 to 5 mm) is enough.
8 Put the mini greenhouse in a location where it will get medium shade. An east-facing window is good if the weather outside is cold, or a moderately shady area outside if the weather is good. NOTE: Wherever you put it, it should not get too much direct sun. Even a mini greenhouse can quickly get up to seed killing temperatures in hot direct sun.
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Check on the greenhouse daily, as the peat pellets can dry out quickly once the water from main soak evaporates. Before the seeds sprout, they can survive getting too dry once or so. But as soon as they sprout, they can die in a matter of hours if they dry out. If the peat pellets start getting too dry, use a spray bottle to dampen them again. You may need as much as a whole squirt per pellet to dampen to the interior of the pellet.
10 You may see a sprout within 10 days from planting, though the bulk of germination will occur after at least 15 or 20 days. Different species have different germination rates, so don’t get disappointed too soon.
11 If any of the sprouts get tall enough to touch the plastic dome lid while others are still getting started, prop the lid up as necessary to prevent the leaves from touching it… Any leaves resting against the lid will quickly rot and risk killing the seedling.
12 After about 30 days, most of the seeds that are going to sprout with this method will have done so. Transplant all of the healthy sprouts into 4 qt. (or half-liter) pots using the next few steps. But don’t discard the rest of the seeds yet, as we will jar a few more into action by changing the conditions for them.
13 Mix a good potting soil with about 50% small bark-chip mulch. This makes a potting mix with very high drainage that is good for bamboo.
14 Put a little (1/2 inch or 1 cm minimum) of this potting mix into the pots.
15 Move each pellet that has a sprout into a pot and fill around it so that the pellet is buried at least ¼ inch below the potting soil.
16 Give the pots a good dose of water. Because of the really good drainage, don’t worry too much about over watering.
17 Set these pots in an outdoor location that gets about 50% shade and that never gets full hot direct sun for more than a few minutes at a time. These seedlings are now well on their way. You will likely lose another 10% of them for no apparent reason at all, but the rest will have a good chance at making it to maturity.
18 Go back to the tray of remaining un-sprouted seeds and put the plastic lid aside. Store it for future use if you want, but these seeds and seedlings have no more use for it.
19 If your mini-greenhouse tray has a removable plastic liner that helps organize the pellets, take it out and make several drainage holes in the bottom of the unlined tray.
20 Put all of the pellets back in without the liner. Space them roughly evenly, and keep them the same side up as before… Seeds to the top.
21 Fill in around the pellets with seedling mix type potting soil, and mound it up to cover the top of the pellets by about ¼ inch (5mm).
22 Place this tray outside in the medium to full sun, checking it daily to keep it damp but not too wet. Because of removing the dome and the increased sun, expect to need to water nearly every day. It is probably helpful to switch to a regular watering can at this point, as you can give it a more normal dose of water.
23 Hopefully, you will see a whole new set of seedlings start to come up over the next few weeks. As these start to look ready, take them back to step 12 and get them transplanted.
Tips
It is difficult to avoid getting the pellets soggy when first expanding them. Try to only put enough water to get them to expand without getting overly saturated. And, keep in mind that they don’t have to be perfectly expanded in order to be a good effective growing medium.
I have done controlled experiments with seedling soil, rock wool, peat pellets, sand, and variations and combinations of all of them. Under the same conditions, the peat pellets were by far the most successful. And, it is no good having plants germinate only to damage their fragile baby roots while separating them. Peat pellets also avoid this problem, making them a very good solution.
eBay is often a good source for seeds, although you need to be aware of where they are coming from (see the first warning below). Alternately, join bamboo related groups such as can be found on http://groups.yahoo.com or http://groups.Google.com. Many amateur gardeners are happy to share their seeds with fellow enthusiasts.
Warnings
For the first winter in cooler climates, the seedlings will need shelter. Plant the pots in the ground and give an inch or two of mulch. Don’t give them more mulch than that, as it will encourage mice to move in and later to eat the top off of your bamboo.
Expect no more than 30% of the seeds to ever actually sprout. And, don’t be worried if 20% of those die soon after emerging from the soil. You should also not worry if 10% or more of your transplanted seedlings slowly turn brown and die. Unfortunately, this is normal for many species of bamboo. If you end up with 2 healthy plants for every 10 seeds you plant, you are doing good. For some species it is even much worse than this.
For the second round of transplanting where the pellets have been covered with soil, be especially careful with these to avoid damaging the roots. The potting soil gives them the opportunity to send roots out into nearby pellets.
In really cold climates or for less hardy species, they may need to spend their first winter indoors or in a greenhouse. But remember that they need some water even in winter, so don’t just put them in a greenhouse and forget about them!
Importation of dead bamboo products, including stubs, into some countries is illegal due to the need to control the spread of bamboo pests and/or diseases. Be sure to comply with all applicable laws when acquiring bamboo seeds.
Things You'll Need
10 or more bamboo seeds. (Any less and there is a good chance you will not get at least one healthy plant.)
A flat bottomed cake pan.
1 quart or so boiling water.
A mini-greenhouse, which is just a planting tray with a plastic dome cover.
A jar of water and a warm (but not hot) place to put it.
One peat pellet per seed that you intend to plant.
A skewer or a chopstick.
1 or more quarts of “seedling mix"? type potting soil.
