Plant Heat-Resistant Lettuces
As we head into the warm temperatures of summer, plant heat tolerant and bolt resistant varieties of lettuce. Summer crisp varieties, also called French crisp or Batavian, are good choices for summer lettuce crops. Try 'Nevada' with large, open heads of bright green leaves; 'Cherokee' with thick, crisp, dark red leaves; or 'Mottistone' with pretty, maroon-speckled deep green leaves.
Pinch Back Mums and Asters
Now is your last chance to pinch back mums and asters to make them bushy, increase the number of flowers, and reduce the need for staking. Simply pinch or snip the top half to 3 inches of stem off, clipping back to a leaf. Pruning plants after early July can delay or reduce the number of flowers that form.
Cut Back Early Blooming Perennials
When early blooming perennials such as catmint, hardy geraniums, lady's mantle, dianthus, delphiniums, and salvia have finished flowering, cut back the faded flowers to promote a second, smaller flush of bloom later in the season.
Keep Up with Container Watering
Container plantings and hanging baskets have a limited volume of soil and can dry out really fast when the weather gets hot. Some containers may even need watering more than once a day when temperatures reach into the eighties and nineties. If the entire rootball dries out, it can sometimes be hard to rewet the potting soil, especially if it's high in peat. If this happens, add water slowly so that it soaks in and doesn't just run down between the soil ball and the inside of the pot.
Renovate June-bearing Strawberry Beds
When the harvest season for June-bearing strawberries draws to a close, it's time to renovate the bed to keep it healthy and productive. Mow off the foliage using a lawn mower with the blade set high enough to avoid damaging the crowns of the plants, collecting the leaves in the mower's bag, then topdress the bed with compost. A week or two later, trim back the the plants by hoeing or rototilling to reduce the width of the rows by about half. After 3-5 years, it's time to replace the entire planting. Day-neutral and everbearing strawberry varieties don't need this yearly renovation, but for the best productivity, the plants should be replaced every 3-4 years.