Bambi? Or: The Worst Threat To Non Suburban Rhododendrons?
Peter F. Leslie
Changewater, New Jersey
As the rural productive areas and wooded wild areas come under increasing development the deer population of the state of New Jersey continues to expand at the astonishing rate of up to forty per cent per year.
How is this possible since the land is now being replaced by housing? One of the principal reasons is that the drainage and water supply problems of rural and exurban developments has resulted in large lot sizes of three to five acres to insure both potable water and disposal of sewage. In today's society it is usually not economical to develop these tracts totally or the homeowners simply wish to live in as close to a natural state as possible.
This becomes the perfect environment for a deer population explosion since the density of the housing precludes hunting. The remaining brush or understory of the wild portion of the land plus the ornamental plantings provide all the food these animals need. The deer sense that they now are not subject to pressure and feed where and when they want at any time. No longer are they seen only at dusk but are visible at any time of day and ignore human presence.
The New Jersey Farm Bureau, beset by complaints by both its general farm and its nursery members, is conducting a survey of the damage caused by these animals. Based on general wholesale prices in New Jersey a fully budded rhododendron is worth approximately $10.00 per foot of height with increases in the scale as the plant reaches four to six feet. Azaleas tend to be, even more costly. Even ten to fifteen percent damage causes the plant to become unsalable. To the plant fancier, it can cause extensive damage to a collection built up over many years. Nothing is more damaging to the hobby than to see a new hybrid that had set its first blooms eaten away to a single stalk.
The hunting lobby in New Jersey is very strong and resists controls of any sort. Until the plant societies lend a hand to a control effort the chances of change are minimal at best. In the mean time there is little the individual grower can do besides applying repellants. This is a difficult task in winter, the time of maximum damage.
After three years of increasing damage, the writer has noticed some readily apparent levels of damage. As the sole area investigator his conclusions can hardly be called final. In writing military history the axiom is one witness is no witness. The same holds true for general assumptions regarding plants. The following observations need to be examined and tested by others both in New Jersey and other states and provinces where deer are prevalent.
The first conclusion seems to be that Ponticum Series plants in all forms are highly unpalatable to deer. Not only are R. catawbiense and R. maximum almost deer proof but this also extends to their hybrids. In this case it seems that 'Scintillation' for instance must have strong Ponticum genes. Rhododendron yakushimanum seems to be completely immune.
A second series is at the opposite end of the scale. The more of Fortunei there is in a plant the more it attracts deer. Nearing's hardy form of R. fortunei grown in New Jersey not only loses all its leaves but the branches are so tasty they are eaten down to the previous year's growth. All of the Dexter hybrids that are linked, in appearance at least, to Fortunei suffer almost the same amount of damage.
Evergreen azaleas are browsed on until they have lost all of their flowers and branch tips. The result is that they produce spectacular growth due to the selective pruning and become magnificent midsummer specimens with heavy bud set. During blooming time there may be ten flowers on a two foot by four foot plant. Hybrid deciduous azaleas and lepidote rhododendrons suffer much the same fate with the sole exception of true Carolinianums. The native azaleas seem to be spared especially after they are mature and at least four foot tall. The seedlings and transplants are devastated.
A possibly premature conclusion may be that the eastern white tail deer lives in the wild with the native ericaceous flora and both coexist. As long as deer-prone gardens use mature plants of this background it may be possible to maintain a balance. What would happen in a really snowbound winter is hard to fathom. The recommendations of the state agricultural agents to use electric or eight foot high fences are impractical with a modern household of driveways, walks, accessible septic systems, wells etc. Much more research is needed on long lasting repellants and other chemical barriers. In the end the only long term solution may be in animal control.
Peter Leslie, New Jersey Chapter President, enjoys growing ARS seed, collecting wild kalmia seed and growing native azaleas.