Gathering seaweed that has been washed ashore, rinsed free of salt water and added to the garden and compost pile brings essential nutrients for our plant growth. lt is also an effective mulch. Manatee grass, Turtle grass, Sargassum, and Shoal grass are common seaweeds available year-round. In general, seaweed will have near neutral to slightly alkaline pH, with a nutrient value of 1.5% nitrogen, 0.1% phosphorus, and 1.3% potassium or a little bit higher, also containing 5% calcium and 1.3% magnesium.
May is a tough time for fighting mildew, because of moderate temperature and damp air. Organically grown plants tend to have more resistance to mildew than chemically treated plants. Soils fed with organic fertilizers and amendments are full of beneficial fungi and microbes.
You may enjoy trying Malabar Spinach this season. It performs well during warming temperatures, unlike other spinaches, and is not bothered by insects. The vigorous vines can climb to 8 feet, when trellised.
Prepare your asparagus bed with care as it will be the first yield of spring for up to 20 years or more. It will benefit from some afternoon shade in the really hot months, but needs several hours of full sun a day. Choose only cultivars bred for hot climates. Asparagus does its best in lighter soils that drain well, so a raised bed might be the best option. Fertilize in spring and fall by top-dressing with liquid fertilizer (such as compost tea) or side-dressing with a balanced organic fertilizer.
As beans, cucumbers and squash begin to bear, pick daily to encourage them to keep producing.
If you have planted melons near squash, do not save the seeds from them for next year’s garden . The pollinators will have rendered them unpredictable.
By the end of May, the necks of onions will begin to weaken and fall over. Stop watering them to allow them to ‘cure.’
Do not over fertilize beans and tomatoes with nitrogen, as you will encourage more leaf growth at the expense of vegetable development.
As plants weaken in the heat, side dress with compost.
Continue planting beets, chayote, corn, cucumbers, eggplant, melons, peppers, pumpkins, radishes, tomatoes, turnips and herbs.
Hunt and pick young and tender zucchinis daily. (If you have many in the garden, pick and eat the flowers, too.)
Remove cool season annuals that have finished blooming.
Continue sowing sunflowers in sunny spots. Remember that they need a good amount of water until they are established, then they are relatively drought tolerant. Cutting flowers extends the bloom season. Save your seed heads for the birds.
Planting marigolds in the vegetable garden attracts beneficial insect like the Hoverfly (whose larvae eat aphids). The adult Hoverfly works as a pollinator throughout the garden. They are attracted to the orange and yellow of the marigolds.
Prune winter and spring flowering vines and ground covers after they have finished blooming.
Feed your tuberoses with a slightly acidic organic fertilizer. The fragrant flowers will appear in August or September.
Always water zinnias by soaking the ground. Watering overhead will ruin the foliage. Pick and deadhead zinnias throughout the summer.
Divide and mount stag horn ferns.
Plant clematis, cleome, irises, and nicotiana.
Do not apply horticultural oil as it will burn foliage with hotter temperatures.
Treat Otto Luyken Laurels with an oil spray for mites, spraying the back side of leaves. The mites are barely visible, and often are on the underside of leaves. If you suspect mites are attacking your bushes, take a plain sheet of white paper, place it under the branch, and tap the branch. If you see red specks on the paper, you have spider mites. Should the problem continue, apply a mitacide.
Feed and water cycads.
Fertilize azaleas and camellias after they have finished blooming.
Feed avocado and citrus trees.
Use care when operating equipment around your trees. The bark is tender tissue and easily damaged when crashed into, making the tree vulnerable to disease and insect infestation.
Fertilize warm season lawns this month.
If you live in a coastal zone, you may want to feed your cool season lawn with a liquid fertilizer, like fish emulsion, mixed with kelp and humic acid. This combination should be enough to get the turf through the summer.
When you mow, only remove 1/3 of the height of the lawn. The extra height shields tender roots and conserves water.