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Horticulture and Home Pest News
Horticulture & Home Pest News is filled with articles on current horticulture, plant care, pest management, and common household pests written by Iowa State University Extension specialists in the Departments of Entomology, Horticulture and Plant Pathology.

Tips for Earlier Yields in the Home Vegetable Garden

This article was published originally on 3/31/1993
Most home gardeners are anxious for that first ripe tomato or early muskmelon. Gardeners who sell produce at local farmers' markets also strive for the earliest crop possible because early produce often brings better prices at the market.

There are several techniques gardeners can use to hasten growth and production in vegetable plants. Listed below are a few ideas you may want to try this year.

Early varieties. All varieties of a vegetable do not mature at the same time. One way to obtain earlier yields is to select varieties that mature in fewer days. There may be some sacrifice in fruit or ear size with the earlier varieties, so you may want to plant a later maturing variety for mid-season production. Some of the recommended early varieties are:

muskmelon'Earlysweet'
tomato'Spring Giant', 'Pik Red', 'President'
potato'Red Norland', 'Irish Cobbler'
sweet corn'Earliking', 'Earligem', 'Earlibelle', 'Aztec', 'Sundance'
cabbage'Gourmet', 'Heads Up'
Transplants. Starting plants indoors and setting them out as young seedlings often gives gardeners a few weeks head start on the season. Crops that grow well from transplants are: tomato, pepper, eggplant, cabbage, cauliflower, broccoli, kohlrabi, onion, cucumber, muskmelon, watermelon, and squash. Previous issues of this newsletter have discussed the production of garden transplants.

Tips to remember when using transplants to enhance early production are:

  • Set out small, stocky transplants. Avoid those that have fruits or flowers. Cucurbits, such as cucumbers, melons, and squash, should be set out when the first true leaf appears. This is around 21 days after seeding.
  • Transplants should be properly hardened-off before planting in the garden.

Black plastic mulch. For several years, commercial vegetable growers have used black plastic mulch to produce earlier yields. It is now widely available to home gardeners. Other advantages to using black plastic mulch are that it conserves soil moisture and prevents weed growth around the plants. It comes in rolls 3-feet wide and various lengths. It is used for warm season crops, such as tomato, pepper eggplant, and cucurbits, and is laid at planting time. Some tips for using black plastic mulch are:

  • Lay the plastic on a calm day.
  • Lay the plastic on moist soil.
  • Keep the plastic tight on the soil and weigh down the edges with soil.
  • Punch holes in the plastic to set the transplants through at recommended plant spacings. Do not punch any other holes in the plastic. Water will enter through the transplant holes and spread laterally under the plastic.
  • Most plastic mulches are not degradable and must be removed from the garden at the end of the season.
Hot tents. Covers placed over individual plants are often called "hot tents" or "hot caps." They protect the young transplants from wind and cool temperatures. It should be noted, however, that they only provide frost protection down to 29 or 30 F. It is also important to provide some type of ventilation in the hot tent to permit air exchange.

Hot tents should be left over the plants for only a week to 10 days, depending on the temperature. Yields can be reduced if the plants out-grow the hot tents or if it gets too hot under the hot tents.

There are several types of hot tents gardeners can use. Avoid using tin (coffee cans). Gallon milk jugs with the bottoms cut off and the caps removed work well as hot tents. Place a thin stake through the opening in the milk jug to secure it to the soil. You may also want to mound soil around the sides. Regularly check plants growing under milk jugs and remove the milk jug before the plant becomes too large.

Wall-O-Waters. Wall-O-Waters are similar to hot tents. However, they provide much longer protection for the plant. They consist of a series of tubes that are filled with water. The Wall-O-Water is set up in the garden 6 to 8 weeks before the typical planting date. It should be set up and filled with water a week before the transplants are planted through them. This will warm the soil in that area.

To fill the Wall-O-Water, place it over a 5-gallon bucket. Fill each tube 2/3 full of water. It will lean inward to form a "tepee" around the plant. The Wall-O-Water will protect plants to 16 F. When outside temperatures drop below freezing, the water inside the Wall-O-Water will freeze. As the water freezes it gives off heat, keeping the temperature inside the Wall-O-Water above freezing. When outside temperatures become warm, the tubes in the Wall-O-Water can be completely filled with water so that it stays open. It can remain over the plants for up to a month after the last frost date. In demonstration garden trials throughout Iowa, the Wall-O-Water resulted in earlier fruit production on tomatoes. However, they did not work well for muskmelon.

Floating row covers. Floating row covers are lightweight "fabrics" that are laid over a row of plants to protect them. They are composed of spun-bonded polyester and come in various widths -- 6 feet or wider. Floating row covers are designed to retain heat while allowing light and water through to the crop. The row cover material is about 85% transparent and may provide protection down to 28 F. Floating row covers are available to gardeners under trade names such as Reemay and Agryl.

This product is intended to "float" over the row with edges held in place with soil. However, strong Iowa winds whip the row cover material around and cause abrasion on the young seedlings. It performs best when stretched over hoop supports spaced every 5 feet down the row. The edges should be secured with soil. Floating row covers are also recommended as a non-chemical insect control strategy. Cabbage, broccoli, and cauliflower can be grown under Reemay that has been stretched over hoops to prevent cabbageworm attack. Be sure to make the support hoops large enough to accommodate the full-sized plants. Some gardeners have used it over young cucumber and muskmelon plants to prevent cucumber beetle feeding. However, it needs to be removed when the plants begin to flower so pollination can take place.

There are other ways to protect young transplants. Wire cages placed over tomato plants can be wrapped in clear plastic to protect the plants from wind and cool temperatures. Some commercial vegetable growers use slitted, clear plastic row covers to protect their plants. The slitted plastic is stretched over wire hoops and secured with soil, resembling a mini greenhouse.



This article originally appeared in the March 31, 1993 issue, pp. , 1993 issue, pp. 33-35.

Year of Publication: 
1993
Issue: 
IC-465(6) -- March 31, 1993