Bud blast is caused by environmental factors, such as late-spring frosts or a lack of potassium in the soil. It often affects young peonies, causing their buds to turn brown and hard when they are about the size of a pea. Get rid of infected areas, and have your soil tested for potassium deficiency.
Thrips are tiny insects that damage buds and flowers by sucking their juices. They cause the discoloring and setbacks you describe. To see if your peonies have them, shake the buds over white paper. If you see small gray, brown or yellow cigar-shape insects, you have thrips. Remove and discard the affected buds.
At the end of the season, always cut back and discard dead plants. Any remaining foliage gives pests and diseases a place to hibernate.
Rumor has it that peonies need ants in order to bloom. It's not true. But the insects do like to feast on sap secreted by the buds, and then on nectar once the flowers unfurl. Ants won't harm the plants, but if you're planning to bring blossoms into your house, remove the insects with a gentle spray of water.
Q: Why does the lettuce I'm growing taste bitter?
A: Throughout most of the United States, it's best to grow lettuce in spring and fall, though areas with cool summers, such as Maine or the Pacific Northwest, can often produce tasty lettuce all summer long.
Heat causes the plant to bolt, which means that it produces a flower stalk; this makes the leaves harsh tasting. An inconsistent watering schedule can also infuse lettuce with an unpleasant flavor.
To grow the best-tasting lettuce, sow seeds every few weeks until temperatures are consistently in the 80s, and again in late summer as cooler days return, continuing until there is frost.
