Feeding your summer vegetables
Now that your summer vegetable crops are in the garden, it's time to talk about getting them to harvest.
Tomatoes, peppers, eggplants, and other summer fruiting crops will benefit from a side-dressing of fertilizer when they first set fruit and every four to six weeks thereafter.
Feed your fruiting crops that have flowered and set fruit with liquid balanced fertilizers such as homemade compost tea, comfrey tea or with store-bought solid organic fertilizers in powder, pellet, or granular form.
Liquid organic fertilizers like compost tea can be watered-in around the base of plants or applied directly to crop leaves as foliar feeds. Solid fertilizers are best applied as a top dressing or band of fertilizer around the base of each plant.
Here are some crop feeding tips:
ο If you prepared your planting beds with a manure fertilizer, reduce the fertilizer rate by one-half. Manures are generally high in nitrogen. A balanced fertilizer contains equal or near equal parts nitrogen, phosphorus, and potassium.
ο When using a commercial organic or non-organic fertilizer, always follow the label directions on the package. Too much fertilizer can be as or more harmful to plants than not enough.
ο For higher yields of fruiting crops such as tomatoes and peppers, extra phosphorus and potassium should be given after flowering and fruiting. Use an organic fertilizer with a 5-10-10 NPK formula.
ο For higher yields of leafy crops and crops that have overwintered in the soil such as autumn-planted onions, a top dressing of nitrogen rich fertilizer will act as a crop booster.
ο It usually takes 10 to 12 weeks from the time transplants are set in the garden for tomatoes, peppers, and eggplants to ripen their first fruit. Fertilize these crops with a side-dressing, one month and then again two months after transplanting - as a guide.
ο Vegetables can take a limited amount of nutrients in through their leaves; this is called foliar feeding. Use a watering can with a fine nose and foliar feed with compost tea, comfrey tea, or seaweed extracts.
ο Foliar feeding is particularly helpful as a boost or tonic for plants that are lagging or off to a slow start. Foliar feeding commonly results in plants gaining a deep green, healthy look soon after feeding.
ο Dry fertilizers are generally watered in after they are applied as a side-dressing. Foliar feeding does not require watering of the soil before or after applying fertilizer. Foliar feed when the soil is already moist or when the weather is particularly dry and plants can use both a watering and fertilizer application.
ο Homemade Compost Tea Recipe: Put two shovelfuls of compost into a burlap or coarsely woven sack, laundry bag, old pillow case, or old pair of socks or pantyhose. Tie the top shut and place the bag in the bottom of a bucket, trash can, or barrel. (About one part compost to five parts water.) Let it “brew” for seven to 10 days. Dilute the resulting “tea” with water until it is light brown or the color of weak tea and use. Water your compost tea in at the base of plants. One note: when you are brewing compost tea, put a cover over the brew. This will keep harmful bacteria from dropping into the brew.
ο Compost Tea Foliar Spray: Brew your compost tea as described above. Pour the solution through a cheesecloth strainer into a hand or pump sprayer, dilute to the color of weak tea, and spray on the foliage of crops. Compost tea will act as a fungicide: beneficial microorganisms in compost tea feed on harmful fungi responsible for many foliar diseases such as powdery mildew and downy mildew.
Best time to feed summer crops
Beans: not really necessary.
Corn: Three weeks after planting or when plants are 8-10 inches tall; again when tassels appear.
Cucumbers: Just before vines start to spread and again when blossoms set.
Eggplant: Three weeks after transplanting and again at blossom time.
Melons: Just before vines begin to spread; a week after blossom set; again three weeks later.
Okra: At blossom time.
Pumpkins: When plants start to run; again at blossom time.
Summer squash: When plants are 6 inches tall; again at blossom time.
Tomatoes: Two to three weeks after transplanting; at blossom time; before first picking; two weeks after first picking - always light on nitrogen.
Zucchini: At blossom time.
Steve Albert is the author of The Kitchen Garden Grower’s Guide available at Amazon.com. He teaches in the landscape design program at the U.C. Berkeley Extension. He lives in Oakmont.