Ask the Master Gardener September 2010
Q. We have a raised bed that is about 7 inches deep. The soil is dark-colored and was excavated from the foot of a slope in a woods near a graveled road. I also added several bags of muck topsoil.
I have tried to grow several vegetables, but the stems of all are very elongated. Radishes were about 18 inches tall with very small underground parts. Lettuce was about 12 inches tall with small leaves. Tomato vines are about 6 feet tall with thin lateral branches about 5 to 8 inches apart. A few tomatoes have developed near the ends of the vines. I have tied the vines to trellis.
I have fertilized the tomatoes but not excessively. I have watered when needed. Other flowers, grass and shrubs growing nearby on the natural soil, which is shallow to clay, seem to grow normally. What could be causing this strange growth pattern?
A. Since you are getting a lot of presumably healthy foliage growth but poor root and fruit development, I would suspect low potassium and/or phosphorus. If you have not yet had the soil tested for nutrient status that should be your next step.
Q. What is the best way to get rid of strawberry plants? They have not produced anything for years. We have tried pulling them out, rototilling, etc., but they keep coming back. The patch is about 6-foot x 2-foot in size.
A. It is amazing how vigorous plants can be when we want to get rid of them! A non-selective systemic herbicide such as glyphosate is generally pretty effective, especially when applied to the green foliage in late summer or early fall, as there is good translocation of the product to the roots at that time. If you want to avoid using herbicide, you could also try covering the area with sheets of plastic to heat the plants and soil and hopefully kill the strawberry plants for good. Clear plastic will allow you to monitor the progress, but black plastic can also be used. It is hard to know how long to leave the plastic in place. The hot summer weather would have been a good time to do this, but there should still be enough time yet this fall to generate sufficient heat.
Q. We have two peach trees that have so many peaches each year that the limbs break down. The peaches aren’t much bigger than golf balls. I was wondering what would be a good rule of thumb as to thinning them? My husband says to let Mother Nature do it, but I think she needs help since they are so little.
A. You win this round! Heavy fruit loads not only result in smaller, less-quality fruit but, as you’ve experienced, the weight can cause the limbs to break. Mother Nature will do some thinning, but generally not enough in a good fruiting year. Most fruit trees have at least two waves of fruit drop. The first occurs shortly after bloom, resulting from lack of or incomplete pollination. The second drop occurs three to four weeks later and is usually bigger and more dramatic because the fruits have developed to a larger size, usually one-half to 1 inch in diameter. This second drop is called “June drop” (because it usually occurs in early June). Competition among the fruits for water and nutrients is thought to be the cause of June drop. Fruits that contain the fewest or weakest seeds are usually the first to drop.
Although June drop may appear to be devastating, many trees do not shed enough fruit naturally for good production of the remaining fruit. For best quality, some hand thinning is recommended before the fruit is halfway to maturity. Peaches should be thinned to about 4 to 5 inches between fruit. If you simply cannot bring yourself to remove the excess fruit, be prepared to prop up heavily loaded branches.
Q. I have been harvesting seeds from various roadside plants to grow next spring. Should I be leaving them outside to experience the climate change and so to better ensure success in growing them?
A. The many species of plants in our climate vary in their requirements for germination. Some will bear dormant seed that needs to go through some physiological maturation before they will be able to germinate. Others may have a hard seed coat that needs to be softened or abraded to permit germination.
The most common type of dormancy is overcome by moist-chilling, also called stratification. In nature, seeds are stratified as they lay in cold, moist soil over winter, but they may never actually germinate. The seeds may become buried too deep, damaged by insects and animals, or become excessively dry or wet. Gardeners can stratify seeds in a more controlled manner by placing the seeds in moist packing material, such as peat moss, vermiculite or sand. The refrigerator is just about the right temperature to provide the chilling. Although the length of the chilling period varies with the plant species, most seeds are adequately stratified for three to four months at 35-40 F.
Things to do in September:
Prepare storage areas for overwintering tender flower bulbs and garden produce.
Thanksgiving (or Christmas) cactus can be forced into bloom for the Thanksgiving holidays. Provide 15 hours of complete darkness each day, for instance, from 5 p.m. to 8 a.m., for approximately eight weeks. Keep temperature at about 60 to 65F. Temperatures of 55F will cause flower buds to set without dark treatment.
Dig and repot herbs, or take cuttings, for growing indoors over winter.
Store leftover garden seed in a cool, dry place. A sealable jar with a layer of silica gel or powdered milk in the bottom works well.
Bring houseplants moved outside for summer indoors before night temperatures fall below 55F. Gradually decrease light to acclimate the plants and help reduce leaf drop. Check and control insects and diseases before putting these plants near other houseplants.
Poinsettias saved from last year can be reflowered for this year’s holiday by providing complete darkness for 15 hours daily from about Oct. 1 until about Dec. 10.
Fall is a good time to plant many container-grown or balled-and-burlapped nursery stock. Prepare a good-sized hole, plant at the same depth it grew in the nursery and water thoroughly. Mulching will help protect against large fluctuations in soil temperature and moisture. Be sure to stake or guy-wire tall plants to protect them from strong winds. Wrap tree trunks to protect against frost cracks or animal damage.
Do not be alarmed if your evergreens, particularly white pine and arborvitae, drop some older needles. All evergreens shed needles at some time, but not all at once as deciduous plants do.
Harvest apples, pears, grapes, and everbearing strawberries and raspberries. For most fruits, flavor is the best indicator of ripeness, although color change also can be a good indicator. However, pears are best ripened off the tree, and grapes change color long before they are fully flavored, so sample the fruit to be sure.
Remove raspberry canes after they bear fruit.
Clean up fallen fruits, twigs and leaves around apple (including crabapple) and other fruit trees to reduce disease and insect carryover.
To promote the lawn’s recovery from summer stress, apply high-nitrogen fertilizer at the rate of 1 pound actual nitrogen per 1,000 square feet.
Reseed bare spots or new lawns using a good-quality seed mixture.
Early fall is a good time to apply broadleaf weed killers. Be sure to follow all label directions, and choose a calm day to prevent spray drift.
Dig onions and garlic after tops fall over naturally and necks begin to dry.
Plant radishes, green onion sets, lettuce and spinach for fall harvest. Thin fall crops such as lettuce and carrots that were planted earlier.
Harvest crops such as tomatoes, peppers, eggplants, melons and sweet potatoes before frost, or cover plants with blankets, newspaper, etc., (but not plastic) to protect them from light frost.
Mature green tomatoes can be ripened indoors. Individually wrap fruits in newspaper, or leave them on the vine, pulling the entire plant out of the garden. Store in a cool location — about 55F to 60F.
Harvest winter squash when mature (skin is tough) with deep, solid color, but before hard frost. Some cultivars will show an orange blush when mature.
Plant, transplant or divide peonies, daylilies, iris and phlox.
Save plants such as coleus, wax begonias, impatiens or fuchsia for indoor growing over winter. Dig plants and cut them back about halfway, or take cuttings of shoot tips, and root them in moist vermiculite, soil mix or perlite.
Watch for garden chrysanthemums to bloom as days grow shorter. Some may have bloomed earlier this summer, which will decrease the number of fall blooms.
Plant spring-flowering bulbs beginning in late September. Planting too early can cause bulbs to sprout top growth before winter. However, allow at least four to six weeks before the ground freezes for good root formation.
Dig tender bulbs, such as cannas, caladiums, tuberous begonias and gladiolus, before frost. Allow to air dry, and store in dry peat moss or vermiculite.
Cut flowers, such as strawflower, statice, baby’s breath and celosia, for drying, and hang upside down in a dry, well-ventilated area.
- Submitted by Janice Kirchenbauer
