Recovering deer damage on Thuja occidentalis 'Smaragd' - click to enlarge


Mammal Control:

We have tested several methods of deer control including garlic sticks, soap bars, bobcat urine, and coyote dummies. Nothing works as well as the two-punch combination of a sprayed deterrent and physical barrier method.

In the late fall, while the high temperatures are still above 40F, we apply PlantSkydd on the vulnerable plants then cover all our taxus hedges with deer netting.We will again reapply PlantSkydd during mid-winter when daytime temperatures go above 40F. Since we began using these methods in tandem, the damage to these plants has been just about eliminated.

Rodents are unfortunately harder to control. Frequenting our landscape are rabbits, voles, mice, groundhogs, and of course chipmunks and squirrels. PlantSkydd does not seem to work as well on the perennials and annuals these animals like to eat. We have had success covering garden beds of mums with bird netting, which is barely visible, but rodent damage continues to be a battle. Relocation has been a method that has worked well so far. We use Havahart traps and drive them several miles away for their release. We are considering employing a couple domestic cats to guard the property. Encouraging predators also helps.

Frequenting our landscape are turkey, deer, rabbits, voles, mice, groundhogs, and of course chipmunks and squirrels. With predators scarce, these populations are exploding and beginning to do some very noticeable damage. 

Following bulb planting in fall 2012, we tried several different organic control measures to prevent the rodents from digging. All methods proved equally effective, though none lasted into the spring.

  1. Hot Peppers sprinkled directly onto the surface of the bed
  2. 4:1 ratio of water to Ammonia sprayed directly on the bare soil
  3. Bird netting pinned to the surface of beds

2013 Bulb protection plan
Mixed Allium bulbs into 60% of tulip displays.  Kept planting surfaces clean of any bulb paper.  Generously applied chili pepper flakes to the surface of beds.  Saw minimal if any sign of pests going into winter.  Vigilance required in the spring when the tulips begin to emerge.  Deer Pro was applied to any trees/shrubs of interest to deer.  Have seen 100% success rate at week 10.  Continue to monitor fence throughout the winter for breaks or breaches.

2014 January-June
Bulb protection results: Inter-planting the tulips with Allium bulbs seemed to help deter chipmunks from eating the Tulips. There continues to be one area that was heavily eaten. We will switch to mostly Hyacinths in this location, with the hypothesis that the bulb's skin will irritate rodents the same way it irritates humans. Going forward, we will continue to use Allium where the tulips are heavy, as well as spray the soil surface periodically with pest repellant.

In addition to chipmunks, we anticipate browsing deer herds to be a significant threat to many plants. March 2014 saw very heavy snowfall which compromised the deer fence. The long winter season meant that the deer were more inclined to eat treated plants and plants they don't normally feed on. 

For the upcoming winter, we will use a three part approach; first, plants will be sprayed with DeerPro repellant. Second, we will erect a 10' fence around areas and plants where deer are known to browse. Third, we will allow some limited hunting on property. We employed hunters during March of 2014 which was particularly long and snowy, when deer herds were increasingly desperate for food. The presence of these hunters seemed to be enough to deter deer. While no animals were shot or killed, the populations' presence decreased.

2015 January - March

The extremely cold and snowy winter resulted in very little activity for the first quarter of 2015. Our main focus, particularly in the month of March, was on deer control. Our methods included spraying the foliage of all plants at the beginning of winter with DeerPro, erecting a 10' tall perimeter fence, patrolling the property with a dog and employing hunters. At one point in March, the herd reached approximately 40 animals. By then, the snow was hard enough for them to walk on and the fence was dragged down by snow. As we were unable to patrol 24 hours/day, there was still significant browsing damage to the broadleaf evergreens, yews, rhododendron, azalea, etc.

2015 April-June
Deer, rabbit, chipmunk, woodchuck, turkey and vole populations increased.   Bobbex animal repellent is applied weekly, but we are still seeing damage throughout the gardens.  We believe this is due to the lack of canine presence; predators are the best deterrents. 

Winter 2015/16
Temps were mild and there was limited snow cover.  Deer were able to survive deeper in the woods and as a result, we had no deer damage.  However, chipmunks, rabbits, turkeys, etc continue to cause problems.  Our scent deterrents seem to have no effect.  Further research needed.

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