Ground Mulch, Row Covers, and Pollination

Ground Mulch and Row Covers

Plastic ground mulches are sometimes used for early cucumbers and summer squash, as they improve soil temperatures, help control weeds in the row, conserve water, and stimulate early fruiting and productivity. Plastic ground mulches are highly recommended for melon production for the same reasons. Plastic mulch increases soil temperatures by 10 °F in spring which promotes rapid seed germination and better transplant establishment. Commonly used plastics are embossed black (cheapest) and newer IRT (infrared transmitting) films, which are more expensive, but are quite cost-effective where soil warming is important. 

Plastic mulches are laid by machine before planting. Growers commonly use 3- or 4-foot wide plastic mulches, which create a 2- or 3-foot-wide soil cover. Matching the plastic to the laying machine creates the fewest problems during installation. Mulch should be stretched tightly over the bed and have a good seal at the edges. This ensures that the wind cannot dislodge the plastic and pull it out of the ground. Install the drip tape under the plastic at the same time the mulch is laid down. Usually, the mulch is applied several days before seeding or transplanting to allow the soil under the plastic to warm.

Plant and row covers can help protect early plantings from frost or wind-damage and enhance yield and earliness. Hot caps and spun-bonded row covers (known as Reemay) are commonly used. Row covers rest directly atop of plants, but should be weighted down to avoid flapping, which causes leaf damage. Remember that row covers need to be opened or removed as plants outgrow the cover, when the plants begin to flower, or when temperatures under the cover regularly exceed 90 °F. When transplanting, plastic mulches can get very hot, and this can cause stem damage to transplants if they touch the plastic. Be sure to water immediately after planting, or mound some soil around the stem to reduce this problem. 

Pollination

High fruit yields and appropriate fruit shapes are achieved when flowers are properly pollinated. The cucurbits require at least one hive per acre and each flower requires 10-15 bee visits to ensure adequate pollen transfer, good fruit set, and proper sizing. Be sure hives are distributed around the field, and put hives out just before plants start flowering. Keep hives in place for 2-3 weeks and use pesticides with caution during flowering to minimize bee exposure.