Here is a vegetable and fruit planting guide for warm regions for the month of May and a food garden checklist.
In the United States, rising temperatures and rain is probable in all or part of the states in the Gulf and South Atlantic Coasts, parts of the Pacific Southwest and Desert, and along the Pacific Coast. These regions include the U.S. Department of Agriculture Plant Hardiness Zones 7, 8, 9, and 10.
This checklist includes a general guide and specifics for Southern States, the Northwest, Oregon, California, and Southern California.
Vegetables: Sow or plant out cool-weather crops: broad beans, broccoli, cabbage, cauliflower, Brussels sprouts, carrots, Chinese cabbage, kohlrabi, leeks, lettuce, onions, peas, radishes, spinach, and parsnips. Thin out overcrowded vegetable seedlings. Prepare and plant new asparagus beds. Make a second sowing of early peas.
When the danger of frost has passed, set out transplants of warm-weather crops: tomatoes, eggplants, cucumbers, French beans, runner and pole beans, pumpkins, marrows, squashes, and zucchini. Start sowing warm-weather vegetable seeds without protection; check seed packets to make sure they can be sown without protection. Sow sweet corn outdoors in mild areas when further frost is unlikely.
If the weather is iffy, use horticultural fleece or floating cloches to protect crops from frost. Remove coverings when the weather warms.
Plant out tomato seedlings in composted soil and with supports. Tie tomatoes gently, but firmly, to stakes to secure them. Keep tomatoes well watered. The trellis supported tomato will out bear the one that sprawls on the ground. Set out the trellis before setting out the plants, training each branch as it grows. Remember, not to tie too tight or the ties will cut into the branch.
Stake tomatoes, eggplants, and peppers when about one foot high. Keep suckers broken off tomato plants. Prune early tomatoes to 2 stems and stake with 5 foot stakes.
Side-dress corn, cucumbers, beans, tomatoes, peppers, and eggplants with fresh compost as fruit begin to form.
Celery can be planted at any time.
Make succession plantings of salad vegetables such as beets, carrots, endive, lettuce, spinach, radishes, and turnips. These crops can be planted every 2 or 3 weeks from now until the end of August to provide a constant supply.
Plant potatoes and onion sets. Plant asparagus crowns. Choose well-drained fertile soil for potatoes.
As asparagus harvest ends, cut back female plants with berries. Do not over-harvest asparagus so that the plants do not exhaust themselves.
Put stakes, poles, and trellises in place for tall and climbing crops. Support peas with sticks or netting. Erect supports for runner beans.
Start picking broad beans when the pods are finger thick.
When peas stop producing, cut vines to ground (do not pull); replace with summer crops.
Herbs: Make further sowings of herbs; thin out April-sown herb seedlings. Plant or pot up basil seedlings. Make cuttings of pot marjoram, rosemary, sage, and thyme. Divide any straggly mint and thyme plants.
Pests: Watch for insects and signs of disease. Pinch out the tips on broad beans to encourage good pod set and to deter attack from aphids. Watch for root flies on cabbages, carrots, and onions.
Practice regular insect and disease control. Look out for potato bugs, cabbage worm, tomato fruit-worm, vegetable weevil, Mexican bean beetle, bean-leaf beetle, spotted and striped cucumber beetle, pickle worm (on cucumbers, cantaloupes, and squash), lice and young harlequin bugs, and blister beetles. Remove diseased plants from the garden.
Maintenance: Cultivate regularly during early May to destroy all weeds. Water by thorough soaking during dry spells in May. Dig around roots to see if plants have sufficient moisture. Thorough soaking once a week is better than daily sprinkling.
Don’t work the bean patch or among the tomato vines when they are wet. Irrigate them, don’t sprinkle. Irrigation is necessary throughout the summer.
Turn the compost pile.
Fruit trees and berries: Remove the blossom from newly planted fruit trees to direct the plant’s energy into the production of strong new wood. Prune wood damaged by fire blight.
Thin fruit on apples, peaches, pears, and plums when marble-size. Thin heavy-cropping nectarines and peaches when fruit is ½ in (1-1.5 cm) in diameter. Water plentifully when fruit is swelling. Water deeply if weather is dry.
Flowering peach trees will be longer lived if heavily pruned just after they bloom. This eliminates leaf-curl disease.
Keep new canes of blackberries and loganberries separate from the current year’s fruiting canes.
Start thinning fruit on wall-trained cherries, nectarines, and peaches. Remove any shoots that are growing directly toward or away from the wall.
Thin out raspberry canes. Summer-prune gooseberries by cutting back side shoots to five leaves.
Tie new canes of blackberries and hybrid berries to a system of support wires, allowing a maximum of eight canes per plant.
Watch for pests and signs of disease. Use sprays at dusk to avoid harming pollinating insects. Trap larvae on trunks of trees and destroy.
Hang coddling–moth traps on apple trees. Spray against apple scab, mildew, and aphids.
Spray raspberries against raspberry beetles. Apply the first spray as soon as the first fruit turns pink.
Feed fruit trees and bushes. Fertilize grapes.
Harvest strawberries as they ripen. Protect strawberry fruits with straw or black polythene. Cover berries with netting to protect them from birds.
Plant citrus and tropical fruits.
Water deeply in dry weather. Control weeds around bush and cane fruit. Replace mulches removed last month.
Watch for pests and signs of disease. Apply potato beetle dust and repeat every ten days; apply pest control to vegetables, as needed.
Greenhouse and cold frame: Plant greenhouse tomato plants in large pots, or plant them in grow bags. Start to feed tomatoes when the first truss of fruit has set. Water and feed tomatoes, cucumbers, and peppers, never letting the soil dry out. Attach slings or nets to melons as they swell.
Introduce biological controls to keep down pests such as greenhouse whiteflies and spider mites.
Southern gardens: Plant seed of edible soybeans, also plant okra, crowder, and field peas, watermelons (if there is plenty of room), cantaloupe, cucumber, collards, sweet corn, summer squash, tomatoes, bush and pole snap beans, and lima beans.
Set second plantings of tomato plants for August fruiting; plant deep, water well and shade for 3 days. Also, plant tomato seed—about 10 seed to a hill—plants to be transplanted in July for fall fruiting. Set plants of eggplant, pimento, hot and sweet pepper in vacant places made by removal of heads of cabbage, lettuce, mustard, and other cool-season crops.
Northwest: Plant pole and bush beans, cucumbers, and midseason sweet corn. Make successive plantings at ten-day intervals, according to your need.
Transplant tomato, pepper, and eggplant from seedbed to garden; thin plants already in the garden and continue cultivation and weeding.
Plant pumpkins toward the end of the month.
Oregon: Pole, bush, and lima beans should be planted this month; successive seedlings of sweet corn should be kept up until mid-June; squash, cucumber, pumpkin, and peppers go in now, and cauliflower, cabbage, Brussels sprouts, and kale during the first half of the month.
California: Plant beans, beets, cabbage, casaba, cauliflower, celery, corn, cucumber, gourds, kale, lettuce, lima beans, melons, okra, parsley, parsnips, peppers, pumpkin, radish, salsify, spinach, Swiss chard, and tomato. Make successive plantings of vegetables, feed them well and irrigate, if the season is dry.
Southern California: Continual planting around the calendar is possible here.