Coastal and Tropical South
Harvest Root Crops
Don't be in a hurry to harvest either potatoes or garlic. Their space in the veggie patch can go to okra or crowder peas later this month. Keep watering both crops if rainfall is scarce, and fertilize lightly if at all now that the root crops are formed. When the potato plants bloom, begin digging around in search of new potatoes. Garlic is ready to harvest when its leaves turn yellow.
Care for Canna Lilies
Canna lilies can be lovely, but it is wise to keep them from becoming overgrown, flowerless masses. If a leaf comes up but does not unfurl, there's a canna leaf roller inside. Cut that stem down right away and destroy it. Shake an insecticidal dust such as diatomaceous earth or flower garden dust into the crown. Each winter, cut the cannas down and if the plants have been infested, do not compost them. Divide cannas every other year to prevent overcrowding.
Ideally, oleanders are a big blob of a rounded form in the garden. Their strong stems curve gently and reach cleanly for an unseen point like good dancers' arms. Sometimes a branch goes sideways or straight up. Cut that branch out completely. Each branch of an oleander shrub can bloom; if one does not, clip a few inches off its end and fertilize the shrub. To keep their round, rather squat shapes, clip a few inches off the end of stems after the bloom.
Container plants can be the source of pesky gnats that seem to hover above the soil and fly into your face when you approach. Watering stirs them up, and indeed, damp soils seem to harbor more of the pests. You can sprinkle a flower garden dust or pour an insecticide into the top of the pot, but that is almost overkill. To take care of gnats, mix up soapy water and drench the pot until water runs out the bottom. Wait two hours and drench with clean water. If potting mixes should drain, but don't, unpot them before the plants succumb to wet feet. Add finely ground bark and/or sharp sand to the mix to improve its drainage and repot the plants.
Rejuvenate Lagging Daylilies
Daylilies should be budded up and blooming this month. If they're not growing, if the leaves have yellow streaks or are overall a paler green than you'd expect, it's time to rejuvenate them. Cut back the affected leaves, spray the plants with a fungicide and pull away the mulch if it is deeper than 2 inches. Fertilize in a week at half the recommended rate and spray the new growth with fungicide as it emerges.