My carrots this year were a freak show! They were bent and branched and bizarre—nothing like the perfectly straight carrots you see at the grocery store. Where did I go wrong?
Carrots are pickier about soil preparation than almost any other vegetable. They grow best in sandy loam that is loose and porous to a depth of at least a foot. Unfortunately, most of us don’t have perfect soil; one way of getting around this is to grow carrots in a raised bed, where you have greater control over the soil quality.
If you garden where the layer of topsoil is shallow or heavy with clay, choose varieties that form short, stubby roots or one of the globe-shaped varieties, such as ‘Thumbelina’ or ‘Parmex’. Work the soil thoroughly, breaking up clods and mixing in plenty of finished compost. Sow the seeds where they are to grow; don’t try to transplant seedlings. The root of a carrot seedling may fork if it encounters a stone, clod, or even a chunk of un-decomposed plant debris. Excessive nitrogen fertilizer is another cause of branched roots.
Be sure to thin the seedlings promptly to avoid the twisty, conjoined roots that result from crowded rows. Thin to 2 inches apart if you intend to harvest full-size carrots, or half that distance if you’ll harvest at the “baby” stage. Use scissors to snip off the excess seedlings instead of pulling them out; even the slight root disruption caused by thinning can lead to forked roots in the remaining seedlings. —Doug Hall
My poor blueberry plants look yellow, stunted, and totally unhappy despite my efforts to acidify the soil with garden sulfur. Should I keep adding sulfur until they green up?
Blueberries grow best in soil with a pH between 4.5 and 5.5. (On the pH scale, numbers lower than 7 indicate acidity; over 7 means alkaline, and 7 is neutral.) In the regions of eastern North America where blueberries are native, soils that are this acidic are not unusual. Elsewhere, gardeners try to accommodate acid-lovers such as blueberries by lowering the pH, using garden sulfur or aluminum sulfate.
Sometimes it works. But some soils have another trait that foils the gardeners’ attempts: high cation exchange capacity (CEC). Because CEC represents the ability of soil particles to stockpile mineral nutrients for later use by plants, moderately high CEC is usually considered a good thing. But soil particles can also cling to the types of minerals that increase alkalinity and make it more difficult for the gardener to acidify soil; high CEC soils are “buffered,” in effect, and resistant to pH change. Soils with plenty of clay or humus tend to have high CECs.
If you get a professional soil test, be sure to ask for an analysis of CEC. A measurement less than 20 means it will be fairly easy for you to lower the soil pH with sulfur. Between 20 and 40, pH change is possible but will require repeated applications and monitoring. Above 40? Grow your blueberries in pots. —Doug Hall
I need to store my potato harvest and I keep reading 45 degrees and dry. My basement has a dirt floor, thus making it not really what I would call dry. Underneath the front porch is a closed-off space but I’m afraid the potatoes will freeze there. Any other ideas?
The University of Idaho Potato Storage Research Facility recommends a cool temperature of 45°F and 95 percent relative humidity for potato storage. Unless your basement is so humid that condensation is running down the walls, it is probably your best choice. Potatoes can be kept at temperatures between 35°F and 60°F—but at the colder end of that range, starch in the tubers will convert to sugar, resulting in dark, discolored flesh when the potatoes are cooked. At the higher end of the range, the quality of the stored potatoes diminishes more rapidly and the tubers will be quicker to sprout.
When harvesting and handling your potato crop, protect them from bruises and cuts. It’s okay to give potatoes a quick rinse to remove soil, but don’t scrub them, because any scrapes or breaks in the skin—even microscopic ones—can allow disease pathogens to enter, leading to decay. Allow the potatoes to “cure” for a week after harvest at about 60 degrees before moving them to the cooler storage temperature; this gives the skins a chance to toughen up, helping them to resist shriveling and decay.
Finally, store the tubers in single layers on lath shelves or mesh nursery flats so air can circulate around them. The storage area should be completely dark to avoid the formation of solanine, a toxic alkaloid produced when potatoes turn green. Check on your potatoes regularly and remove any that are going soft. —Doug Hall
How can I take cuttings of coleus? I have a beautiful multicolored coleus that I want to grow again next year. I am told it’s easy to propagate.
There are two good ways to achieve your goal and end up with a bounty of coleus transplants next spring. One way is to take stem cuttings in early fall and root them individually in 4- or 6-inch pots containing good peat-based potting mix. Cut the sections of stem about 6 inches long. Remove the leaves on the lower half and plunge the stems into the moist potting mix. No rooting hormone is needed.
Protect the cuttings from direct sun initially and tent each pot with a clear plastic bag. Once the cuttings take root and begin to grow, remove the plastic and put the pots in a sunny window in a warm, humid room. Pinch the growing tips occasionally so they don’t outgrow their pots. Keep an eye out for mealybugs, scales, and other insect pests; scrub them off with a cotton swab dipped in rubbing alcohol.
A second technique is to carefully dig up a mature plant, transfer it to a pot (with potting mix, not garden soil), and bring it indoors for the winter. Cut the plant back halfway to lessen transplant shock. About two months before the frost-free date in your climate, take stem cuttings from this “mother plant.” Because cuttings made in late winter have less time to outgrow their pots, it’s okay to root them in 2-inch pots or cell-packs.
My grandmother over-wintered coleus cuttings in a glass of water on her kitchen windowsill, but I’ve had better success rooting the cuttings in potting soil. Whatever method you choose, it’s best to have your coleus indoors before night temperatures dip regularly below 50 degrees—the point at which coleus outdoors begins to decline. —Doug Hall