We want to plant some garden plots. Can we use railroad ties as the perimeter sides?
Railroad ties have no place in an organic garden—or any garden where kids play and edible crops are harvested. Wooden ties are traditionally treated with coal-tar creosote, a nasty, tarry hydrocarbon brew that acts as a wood preservative and water repellent. Creosote is toxic and is thought to be carcinogenic to humans. Less-hazardous preservatives are sometimes used on railroad ties today, but even so, they leave the ties saturated with chemicals that you don’t want in your garden.
Instead of railroad ties, choose nontoxic materials to construct the sides of your growing beds. Untreated lumber, logs, stones, bricks, sheet metal, and cinder blocks are a few options. —Doug Hall
Rabbits were gnawing at the bark of my apple trees last winter, so I put spiral plastic tree guards around the trunks. I recently looked under the guards and was alarmed to see split, oozing bark and lots of ants. What went wrong?
The tree protectors you describe are helpful at keeping hungry critters away from tender-barked trees in winter. The white ones also help protect against frost cracking and sunscald by reflecting sunlight. Tree wraps made of burlap and paper are sometimes used for the same purposes.
But whatever style of tree guard you use, you should consider it a seasonal protection. Wait until the tree is dormant in fall to install it, and remove it as soon as the tree begins to leaf out in spring.
As you’ve discovered, these protectors trap heat and moisture around the trunk during the growing season, creating an environment that can attract insects, promote decay, or even foster fungal diseases such as canker. For similar reasons, it’s not wise to mound mulch against the trunk of a tree.
If gnawing animals are a year-round nuisance, fashion wide cylindrical guards from hardware cloth, which won’t trap moisture against the bark. Or use a stinky repellent, sprinkling or spraying it at the base of each tree.
Fortunately, many trees lose their appeal to rabbits as their bark becomes thicker and corkier. —Doug Hall
It’s difficult to plant anything under my maple tree because of the abundance of roots right at the surface. Can I add 6 inches of soil on top of the roots and plant in that?
Most trees have limited tolerance for changes in the soil grade over their roots. Either adding or removing soil in the root zone can weaken or kill a tree. Six inches is enough to smother many trees; I don’t recommend it. Even if the tree survives the added soil, it will immediately send its roots upward into the new soil layer and you’ll be back where you started.
Shallow-rooted trees like maples are a special challenge for gardeners. One landscaping solution is to choose a drought-tolerant, shade-tolerant perennial groundcover to blanket the ground under the tree. Tolerance of dry soil is necessary because of root competition from the mature tree. Plant smaller specimens that can be tucked among the tree roots without damaging them. You can top the area with up to 2 inches of compost, or a mixture of compost and coarser mulch, to help the groundcover plants get established. Don’t forget to water regularly; even a drought-tolerant groundcover will need some help initially to complete with aggressive tree roots.
Another option: Spread organic mulch, like shredded bark, 2 inches deep under the tree, and then add a few containers for floral color. By giving the tree and the potted flowers separate root zones, you’ll ensure they don’t compete with each other. —Doug Hall
At the farmers’ market they charge twice as much for so-called “baby” vegetables. Is there a trick to growing my own?
There are two ways to achieve a miniature harvest: select vegetable varieties that mature at a diminutive size, or plant regular-sized vegetables and pick them before they get big.
In the first category I’d put things like tomatoes, peppers, and eggplants—vegetables that aren’t fully flavored until they achieve maturity. My favorite tiny tomato is ‘Wild Cherry’, about the size of a currant and available from Tomato Growers Supply Co. We’re trialing Burpee’s ‘Cherry Stuffer’ sweet peppers in the Organic Gardening test garden this year. There are tiny eggplants, too, like ‘Little Prince’ from Renee’s Garden.
Other vegetables, including many roots vegetables and leafy crops, develop their flavors at a young age. There’s no need to wait for carrots, turnips, beets, radishes, or onions to reach full size before harvesting them. Kohlrabi, zucchinis, cucumbers, and crookneck summer squash have a superior taste and texture when harvested small. The early thinnings of salad and cooking greens—think of them as microgreens—are deliciously tender. And don’t forget the wonders of new potatoes.
John Scheepers Kitchen Garden Seeds has gotten on the bandwagon with The Happy Baby Garden, a seed collection of kid-size vegetable varieties. Just remember to plant a few extra rows to compensate for the scaled-down harvests. —Doug Hall