Is it OK to put a nail or a screw into a tree to mount feeders, etc., or does this damage the tree? Is there a trunk diameter at which it becomes OK to do? Are there certain tree species that are particularly susceptible to damage?

An occasional nail or screw will not cause significant damage if carefully placed into wood that is greater than 6 inches in diameter. Remember that every wound creates the potential for decay, especially in weakened trees, so keep accessories to a minimum. These sites should also be checked annually to make sure that the outward growth of the tree is not restricted in any way. If needed, remove the nail or back out the screw to allow for this growth.

Certain tree varieties should be avoided if possible. These include birch, dogwood, cherry, plum and Japanese maple.

While planting perennials this fall, I scattered a few bulbs in each planting hole along with Bulb Booster fertilizer.  After backfilling the hole, I watered with a solution of Fertilome root stimulator, which I have used with great success for many years. Is this fertilizer combination a problem for either the bulbs or the perennial?

One should always be careful about overdoing a good thing. While I doubt you caused any harm in what you did using this combination, it would be easy to injure newly planted perennials by using too much fertilizer.

Bulb Booster is a slower-releasing fertilizer product that will provide root building nutrients over a period of weeks to the establishing plant. Fertilome Root Stimulator, on the other hand, provides immediate stimulation to the plant. It contains a root stimulating hormone to help initiate new roots, as well as a mild, water soluble fertilizer to aid in the plant’s establishment.

If the Bulb Booster is mixed with the planting soil, and both fertilizers are used according to package directions, I doubt that any harm would result from this combination. 

I want to move and replant many spring-flowering bulbs (daffodils, tulips, and alliums). It seems like a waste to throw them out because they are only 1 year old and looked great last spring. When is the best time to transplant? Any tips on digging the bulbs up without slicing through them?

Moving spring-flowering bulbs can be done anytime after the foliage has died down, following flowering in the spring. It is important to allow this to occur because the foliage is helping to rebuild the stored food reserves used during the flowering process.

Not all spring-flowering bulbs reflower dependably year after year. Many tulips, for example, do not have enough time to replenish themselves before the warmer weather moves in and dries the foliage. As a result, most tulips flower great the first year, not so great the second year, and often not at all the third.

Bulbs that flower earlier or are better able to withstand warmer temperatures are more likely to reflower year after year. Daffodils and alliums fall into this group.

If you move the bulbs when the foliage has dried, but before it detached from the bulb, you can more clearly see where the bulbs are located. Using a spading fork will make it less likely that you will slice the bulb, but there are no guarantees you will not stab an occasional bulb.