Q: I have a silver maple tree in my backyard that’s over 50 years old, and during the last five years small branches are dying. I’ve heard that maples need a specific fertilizer, as they can’t access all the nutrients in the soil. Please advise if this is so, and what is recommended. — Morrie S.

A: Maples as a group have difficulty utilizing iron in heavy clay soil. The disorder is called iron chlorosis, and the most noticeable symptom is yellowing of leaves. During early stages, the veins remain green with yellowing between, but as the disorder progresses, leaves turn completely lemon yellow and crisp brown lesions and margins develop. Twig and branch dieback are common.

Maples can be assisted by applying a chelated iron product, which is a form more readily absorbed by the tree. The old tale of adding nails to the hole when planting a maple does not supply iron in a form that’s usable.

Chelated forms of iron can be purchased from garden centers. Follow label directions closely for application rates and methods.

Q: I'd like to keep my potted tulips indoors over the summer and see if they flower again next spring. Will it work to keep them in the cool basement in the dark or on the plant stand with occasional watering as if the tulips were outside? We have an entire chipmunk colony that loves to eat any bulbs, so planting outside isn't an option for me. — Celeste K.

A: Potted tulips have difficulty reblooming because the bulbs expend so much strength to produce blooms the first time, they don't easily recharge enough to bloom a second time. To increase chances of rebloom in pots, be sure to fertilize when they are blooming and while the leaves are still green.

Leave all foliage on the tulip plants until the leaves die down naturally, because they’re feeding the bulbs and adding energy. Without the nutrition that additional fertilizer provides, potted bulbs weaken greatly.

Although it’s difficult, you have nothing to lose if you’d like to attempt a rebloom. After the leaves have died down naturally, keep the pot in a cool, dry location for the summer. To rebloom again indoors, repot the bulbs this fall into fresh potting mix, water well, enclose in a plastic bag and keep in the refrigerator for 10 weeks. Tulip bulbs need a yearly winter cold spell before they will bloom.

Because potted tulips are difficult to coax into rebloom two years in a row, starting over each fall with fresh bulbs is the most common way to enjoy tulips indoors.

Q: We recently moved to Fargo and trying to start a flower garden has been a challenge. I was used to deer munching off my plants, but now I’ve had voles eating my milkweed, and just about any flowering plant. I’m about ready to use metal flowers and colorful bowling balls to bring color to my yard! What flowers can I plant that voles won’t lunch on? — Karl R.

A: When voles are hungry enough, there probably aren't any plants that are lunch-proof. The preferred methods are trapping, such as with rodent traps baited with peanuts or peanut butter, repellents and poisoned baits. Rodent baits can be quite effective in areas of vole activity, placed inside sections of PVC pipe to keep the rodent poison safely away from pets or children.

Vole populations do run in cycles and I didn’t see as many this past fall as in previous years. Hopefully they’re trending downward.

If you have a gardening or lawn care question, email Don Kinzler, NDSU Extension-Cass County, at donald.kinzler@ndsu.edu. Questions with broad appeal may be published, so please include your name, city and state for appropriate advice.