All posts by Irena

Trellising with Bamboo

Bamboo can be an invasive plant, but it’s also an eminently sustainable material with countless uses. Here at Southern Exposure, we frequently use bamboo in our trellises, combining it with a wide variety of other materials.

For pole beans, (whether snap, asparagus, lima, or runner beans) we tie bamboo poles, with the branches removed, to our T-posts to add to their height. Then we tie netting to the poles. Stubs of bamboo branches can give your twine something to hang onto, ensuring that the netting doesn’t fall.

For malabar spinach, we put in one T-post for every two plants, then put a tomato cage made of concrete reinforcement wire on each T-post, then tie two stalks of bamboo, each about 7 ft tall, with the branches still attached, to each cage.

Each bamboo stalk is situated roughly over a malabar spinach transplant. The malabar spinach winds around the tomato cage and around the bamboo branches as though they were a seamless unit.

For Mexican Sour Gherhins, a new, experimental crop for us, we put a tomato cage in the ground (the store-bought, cone-shaped kind), then leaned four bamboo branches against it, so that the base of each branch was next to a Gherkin transplant. We tied the branches to each other above the cage, then tied them to the top of the cage as well.

These trellises blew over in the wind a couple times, so we used a post driver to pound a sturdy, unbranched bamboo pole into the center of each little trellis, and tied the post to the branches. Then the trellises stopped blowing over. Now the Mexican Sour Gherkins can safely wrap their tendrils around the bamboo branches.

For some of our edible gourd trials, we’ve built loosely latticed bamboo trellising. We started with T-posts and concrete reinforcement wire tomato cages at wide intervals. We strung long, branchless bamboo poles horizontally through the cages, then added vertical, branched bamboo tops at frequent intervals, then tied the vertical bamboo to the horizontal bamboo.

Of all our bamboo trellises, the simplest one to make was the one we use for the wild passionfruit (maypops) that grow next to our barn. I simply gathered bamboo scraps from our other trellising projects, leaned them against the second-story barn porch and against each other, and then tied the tops of the tallest pieces to the porch railing.

If you or your neighbor has a bamboo grove, it probably needs to get reigned in regularly. The byproduct of this reigning in can be used for many styles of creative trellises, far beyond those described here. However, remember that very young bamboo stalks (those that have just leafed out) are not strong. Use older stalks for trellising. Our bamboo stalks develop a chalky surface texture as they mature. Also, while you can pound bamboo stalks directly into the ground, this method takes more effort than pounding T-posts, and it’s only effective for small trellises or relatively lightweight vines, with posts at relatively frequent intervals.

Saving Lettuce Seed

We’ve been trying to grow and offer seed for Cosmo lettuce. But we have only a little bit of experience with saving lettuce seed on our own farm, so it’s challenging to get a good seed crop of a large enough size.

We let the lettuce head up, then bolt, becoming too bitter to eat, then flower, and finally make seed. (Lettuce plants become a lot bigger when they bolt and flower, so before they bolted we made more room by harvesting every other head for eating.)

Although it’s possible to save lettuce seed outside, even in our wet climate, growing it in our high tunnel keeps the rain off of the seedheads. This greatly increases our chances of getting a good germination rate and being able to sell the seed. We’ve put up a rope around the bed, tied at waist height to six posts, so that the lettuce stalks can lean on it and so that the seedheads won’t lie on the moist ground. Nonetheless, our first harvest looked terribly disappointing.

It’s been a wet spring, and this harvest came after a period of much rain and humidity. I thought we had a crop failure – too little seed to be worth the time it would take to separate it from the chaff. I almost gave up. I moved lettuce seed harvesting down on my list of priorities. But the next harvest, after a couple days of dry weather, gave me a pleasant surprise.

This time, when I shook and rubbed the seedheads over my tray, a significant amount of mature-looking seed fell out along with the chaff. However, it seems some of the seedheads dried up before producing good seed. Shaking old, dry seedheads still basically just gave me chaff, not seeds. A day later, there was rain in the forecast, so I collected a small, early harvest.

I was quite surprised that I got so little chaff and so much seed. Of course, even this seed will need to be winnowed and screened to clean off the chaff. Then its germination will need to be tested before we’ll know if we have enough good seed to list this variety.

For more on how to save seeds, see our Seed-Saving for Home Use handout. Later this year I’ll post more information on how to clean seed by winnowing with a box fan.

Cicadas in the orchard

The 17-year cicadas are starting to lay eggs in young tree branches on our farm in central Virginia. We’re not worried about any effects of the cicadas on our gardens, and trees of significant size will at least survive.

However, we made the mistake of planting several young trees last fall – persimmons, jujubes, and other fruit trees. Had we known that it would be a cicada year, we would have held off. Such young trees can be severely injured and even killed by cicada oviposition, so I’m experimenting with loosely covering the trees with pieces of a garden blanket. I’ve put bamboo tops – old enough for the bamboo leaves to have fallen off – inside some of the blanket pieces to keep the blanket material from pressing too much against the trees’ leaves and branches. I’ve used pins and rubber bands to seal the openings in the garden blanket pieces and keep cicadas out.

However, cicadas already had laid eggs in some branches of most of these trees, and in the trunk of one unfortunate little pear tree that we’ve had for a couple of years. So I bound that half-inch-wide trunk, and many of the affected branches of our other young trees, in sealing/ grafting film.

I’m hoping the sealing/ grafting will help the branch tissues knit back together, and that it might possibly restrict the eggs’ access to oxygen. I wish I knew if cicada eggs cause the branches to split down the middle as the eggs grow, and I hope I’m reducing the risk of that. But the sealing/ grafting film and the garden blankets are both entirely experimental measures, and I chose them in part based on the materials we had on hand. I hope the trees won’t heat up too much inside the garden blankets, and I hope I’m not using so much grafting film as to cause mold on the branches.