My hydrangeas are not faring well this year. Leaves have brown edges and flowers are not a full head. There is a lot of new growth low to the ground. Is there something I did that caused this?

Most hydrangeas, especially big-leaf hydrangeas, flower on the previous season's wood and can be susceptible to cold damage. This past winter stayed warm for so long that plants did not harden off properly, then it was very cold and we had late spring frosts. Blooms on many hydrangeas are minimal or nonexistent this year — though the roots survived, as new stems attest. Our native hydrangea, Hydrangea arborescens, and some cultivars like “Endless Summer” bloom on both old and new wood, so even though there was winter damage, they will have summer blooms. This spring's extensive wet period followed by drought may account for the brown leaves. Keep hydrangeas evenly moist. Hydrangeas grow best in morning sun and afternoon shade.

Where do lettuce seeds come from, since lettuce has no seeds?

When allowed to continue growing long enough, lettuce will “bolt,” or go to flower. The flowers produce seeds. To harvest seeds, place a small paper bag around the flower head so falling seeds are not lost. Be sure to let seeds develop and mature while on the plant. If harvested too soon, seeds will not be viable. It is not easy to collect lettuce seeds. Most folks buy seed packs.

University of Maryland Extension's Home and Garden Information Center offers free gardening and pest information at extension.umd.edu/hgic. Click “Ask Maryland's Gardening Experts” to send questions and photos.