Q: My hydrangea won’t bloom. Why?

A: This issue occurs with bigleaf hydrangeas (Hydrangea macrophylla), which includes mophead and lacecap varieties. These bloom in July and August and then set buds for the next summer. Prune at the wrong time and you’re in for a blossomless season. The easy solution: Don’t cut it. If the shrub is too large, move it to a roomier spot.

A hydrangea that still doesn’t flower may be losing its buds to cold winters or an unexpected freeze. You can replant it in a sheltered area or wrap it in burlap during chilly months.

Another option: Plant one of the newer cultivars, such as “Endless Summer.” These form buds after blooming and again in spring. If the first set falls victim to errant pruning or harsh weather, the shrub will still flower.

Q: I’ve heard that fiddlehead ferns are toxic. Is this really the case?

A: To many, the asparagus-like taste and pleasantly chewy texture of fiddleheads herald spring’s arrival. The shoots of the ostrich fern (Matteuccia struthiopteris), fiddleheads get their name from their shape: The tightly coiled shoots resemble the scroll carving on a violin. They grow near streams and rivers in the eastern half of the United States and Canada and are harvested by hand.

Even though fiddleheads have been consumed for centuries — if not longer — researchers aren’t sure whether they contain a toxin. The shoots have been linked to cases of food poisoning. In 1994, health officials reported that 75 people in New York and Canada got sick after eating raw or lightly cooked shoots. A few similar episodes have occurred since. Alfred Bushway, a food science professor at the University of Maine who has studied fiddleheads, hasn’t seen evidence that they contain a toxin. One theory that explains the cases of illness: contamination from agricultural runoff or bacteria in river water. Whatever the cause, the Centers for Disease Control and Prevention recommends boiling the shoots for at least 10 minutes or steaming them for 20.

“If that was my only option, I wouldn’t serve them,” says Sam Hayward, a James Beard Award-winning chef and co-owner of Fore Street restaurant in Portland, Maine, where fiddleheads are blanched and briefly sauteed. “They would be flavorless, drab and mushy,” he says. “We trust our foragers. No one has reported a reaction to fiddleheads we’ve served.”

Still, even if food poisoning from fiddleheads seems unlikely, avoid eating them raw.

Q: How do I keep birds from nesting in my hanging plants?

A: Hanging plants are especially attractive to nesting birds. Because pots are often hung under eaves, they offer a measure of shelter from the elements, and because they’re elevated, they provide protection from predators such as household pets. But birds can leave quite a mess behind. The best way to deter them from nesting in pots is with a barrier such as garden netting (available at gardeners.com), which you can cut to size. To prevent birds from becoming tangled, keep the netting as taut as possible, secure it tightly around the pot and its hanger, and trim the edges.

If you discover that a bird has settled in despite your efforts, do not disturb it. In the U.S., it’s against federal law (the Migratory Bird Treaty Act of 1918, specifically) to move nests or tamper with the eggs of migratory birds.