Root Crops and Dwarf Berries

Get those root crops in the ground! March is a great time to plant beets, carrots, onions, turnips, potatoes and radishes. If you planted radishes last week, chances are they are ready to thin. As we discussed on "Garden Talk" this morning, thinning is essential for many types of food crops. Although it is often difficult to convince beginning gardeners to do so, thinning actually increases yield, because each plant has enough room to perform at its best.

In the case of radishes, they should be thinned early, before true leaves have appeared, for the best quality roots. Leave about two inches between plants. Carrots also demand thinning, and the delicate seedlings should not be left crowded too long. Carrots planted this week will probably not appear above the surface until early April. Besides the approaching cold snap, natural germination inhibitors keep the seeds dormant until they have been wet a few times. Thin carrots to stand three or four inches apart for the largest, most uniform roots, unless you are growing a smaller variety, such as 'Little Finger.' Do this as soon as the feathery true leaves begin to appear. In the case of both radishes and carrots, it is best to snip off the excess seedlings at soil level, rather than pull them, because pulling may injure the roots of neighboring plants.

Radishes and carrots may be planted together in the same row. By the time the carrots germinate, the radishes will be almost mature. The emerging radish seedlings break the soil surface, making it easier for the weaker carrots seedlings to follow them. When you harvest the radishes, you will automatically thin some of the carrots.

For gardeners who just hate to thin, I suggest using seed tapes. They are available for many popular varieties of vegetables with small seeds or that are difficult to thin. Essentially, seeds are evenly spaced out between two thin strips of paper tape. You simply lay the tape in the row and the seeds end up at the correct spacing. This is a big time saver, but the tapes are expensive compared to loose seed.

March and early April provide perfect weather for transplanting nursery stock, and all varieties of fruit and flowering trees and shrubs are showing up in local garden centers. This year, check out the Brazel-berry varieties of blueberries and raspberries that have only recently been introduced into the market. "Brazel-berries" are dwarf varieties of raspberry and blueberry, suitable for small garden spaces or even patio containers. 'Raspberry Shortcake' offers the added benefit of being thornless. Grow it in neutral soil in full sun and harvest berries in mid-summer. The two new brazel-blueberry varieties being offered at Stanley's Greenhouse this year are 'Peach Sorbet' and 'Jelly Bean.' Like standard blueberries, these shrubs prefer acid soil, and can be included in the landscape alongside sun-loving azaleas, such as Encore(TM) types. All the brazel-berry fruits can be grown in large containers, making control of the soil pH simpler than in-ground growing. Besides the obvious benefit of fruit, all these shrubs add color and interest to the landscape. Blueberry foliage turns pink and purple in the fall, too. More information and images at www.brazelberries.com

February Planting Time

This week, we planted arugula, celery, chervil, cilantro, corn salad, curly parsley, Italian parsley, and scallions. The arugula and corn salad will be grown to maturity indoors, while the others will be ready for transplant to the garden in early March. This sowing is part of our evaluation of the LED lighting system I have mentioned in previous posts. 

Leek seedlings have grown beautifully with this light source. They were sown in January and are averaging about 4 inches in height. The plants exhibit no sign of yellowing or etiolation. Preliminary results, therefore, are encouraging. The use of LEDs in horticultural lighting remains somewhat experimental, but holds great promise. Electricity consumption is greatly reduced without sacrificing light intensity, making LEDs much more energy efficient than either fluorescent or metal halide sources, the two most commonly used in horticulture. The 20-watt unit I am evaluating adequately illuminates an area roughly the size of two standard nursery flats, sufficient for my backyard garden’s transplant needs.The difference in the size of the seedlings between the two photos is the result of only four days' growth.

If you were planning to add fruit or nut trees or berry bushes to the garden, February is an ideal time to transplant them. Strawberry plants should also be appearing in garden centers this month. Everbearing varieties will give you a decent crop this year, if planted early. Pick off and discard the blooms that may appear in late spring, to give the plants a chance to build a root system. This will not only improve the fall crop, but increases productivity for next spring and fall. If you’ve never grown strawberries, try ‘Sequoia,’ a widely available everbearing variety that produces big, flavorful berries all season once established. We are going to be renewing our planting of this berry this season. The strawberry patch needs relocation about every three years.

Other berry crops that perform well in the Tennessee Valley are blackberries, raspberries and blueberries. Among nut trees, native hickory and black walnut are good choices if you have plenty of room and patience. American filbert is more suited to the backyard garden, but typically only bears every two or three years. Fruit trees require attention to perform well here. June-bearing apples are perhaps the best adapted to our climate, but fall apple and pear varieties regularly appear at the local farmer’s markets. Local peaches also show up at the markets, too. Attention must be paid to pruning and pest control for fruit trees.

One fruit we seldom see in the market is cherries, which is surprising, because my grandparents always had an abundant crop from two sour cherry trees that my grandfather planted in the early 20^th Century. We also had a massive sweet cherry tree, far from the house, that undoubtedly had been planted by my great-grandfather, as it was a foot in diameter when I was a boy. All these cherries eventually succumbed to disease and were removed. They remain a challenge to grow here, owing to a plethora of diseases, but it can be done with dedication. For the backyard gardener willing to take up the challenge, ‘Montmorency’ is a traditional cultivar.