Many of the questions I get concern faltering plants, from those with meaningless spots on their leaves to others already in the grave, and yet others somewhere in between.
I have always wished I knew more of plant pathology so I could at least have a fair shot at diagnosing whatever troubles the plant in question. Since I don’t have much knowledge of that subject, my guess often is no better than yours.
Consequently, let us herewith look at some garden problems that I do know something about, mostly as a result of my ornamental horticulture degree from SHK, the school of hard knocks. Which school, though the academics are rated right at the top, the expended effort in attaining them comes at a precious cost, i.e. lost plants from whatever reason, and some of that having little to do with bacterium or related diseases. I would say offhand the most questions I get concern moles (which many times are actually voles), then pruning (and particularly hydrangeas), and then perhaps deer (which actually are deer).
Moles, with an “m” are entirely carnivorous, that is, they eat only meat, alive or dead. The ridges they make all over a lawn are feeding runs, from which they harvest mostly white grubs, but occasionally earthworms. Their tunneling near the surface doesn’t do serious damage, but when they go down to take up housekeeping at a deeper level there’s trouble ahead. Moles breed like, well, moles and where there was one (no, two) moles, soon there are little ’uns galore and they have to be fed. More grubs gone.
The deep runs made by moles cause untold havoc, not the least of which is opening sluiceways for water. I have found out again this drought year, when watering a certain plant on a slope the water I thought was succoring dry roots was actually traveling through mole runs and exiting sometimes 50 feet or more downhill. No wonder droughts are so destructive, when moles are at their aid and abetment. When moles invade a cultivated bed or border that has soft soil wrought at the hand of years of hard work more havoc results. I have a red border that I have worked at for years, with mostly red and orange ingredients. Moles, a whole family of them, appeared this year and tunneled around almost every inch of the border, uprooting perennials and even young shrubs. Every step taken there has resulted in miring up to at least my ankle, even when the soil was dry from drought. Think what plants are going through just trying to get a little water.
Now, voles, with a “v.” Like moles, voles are seldom seen since they spend most of their life underground. They are the size of a small mouse and can easily consume their weight in roots and bulbs in a day. They are, unlike moles, herbivorous, consuming only plant matter. It is remarkable, and discouraging to the max, the damage several can do in a season.
That red border lost nearly 100 red lily bulbs this year to voles, not to speak of several other perennials. Voles follow mole runs, using them as cafeteria lines to such delectables as mentioned.
In addition, voles have relatives, called lemmings, that are native here also. I always had thought lemmings ran off into the seas in Nova Scotia or somewhere, but there are lemmings here. I found that out when I caught one in a trap some years ago. They are chunkier and a little larger than voles, and eat even more of your valued stuff.
How and when to prune hydrangeas is almost a year-round query. Long story short: For our purposes here, we will divide them into two classes, the mop-headed (most of the time) blue ones with soft wood and the white (most of the time) ones descended from the old pee-gee hydrangea, with hard wood.
The former make their buds a year before bloom (they’re already formed for next year), so late summer and fall pruning is out. The time to prune them is right after flowering. Then, you will sacrifice some flowers that are still presentable to get the stems where you want them. But it has to be done then or lose flowers the next year.
Paniculata hydrangeas, such as ‘pee-gee’ are almost all white, perhaps fading to pink as the flowers age. They flower on new wood of the year, so can be pruned any time after the flowers fade, from fall throughout winter and on into the following spring. They will then flower on new wood.
This is oversimplified, and there are a few exceptions, but this rule will generally work.
To get rid of moles, the best answer is to get rid of the grubs by broadcasting one of several granulated poisons over the area they frequent, thus getting their food supply exhausted, at which event they will move into your neighbor’s digs.
Voles and lemmings can be killed by depositing a wax-based rat or mouse poison into their holes. This is very effective, but it might take a while to get most of them. Caution: don’t let cats or dogs dig into the holes and eat the poison.
The deer? Shoot them.
JIMMY WILLIAMS is the garden writer for The Post-Intelligencer, where he can be contacted on Monday mornings at 642-1162.