How Does Your Garden Grow?
The National Oceanic and Atmospheric Administration has announced that there were a record twelve weather disasters in the US costing more than $1 billion in 2011. The previous record was nine in 2008. Extreme weather events are occurring more often. But, it’s the less catastrophic climatic changes that take a lasting, but hidden toll on our landscape plants, from lawn grasses to mighty old shade trees. And we need to intervene in order to help our landscape investments avoid suffering the ravaging effects of pests and diseases that thrive in these punishing circumstances.
Some symptoms of these stressors may be obvious, such as burnt leaves, grass as dry as straw, and wilting flowers. But, plants often suffer quietly through the challenges of temperature extremes and rainwater fluctuations. After you water a plant that has wilted in the heat, it may look fine but, not really be fine. Trees do not exhibit signs of environmental stress until it becomes chronic. Just as a human with a weakened immune system is more vulnerable to disease, a weakened plant becomes susceptible to a host of opportunistic pests and afflictions.
The Northeast Regional Climate Center reported that the average temperature between January and July was the warmest such period since 1895, the year regional climatic record keeping began. But, extra hand watering or installing an automatic irrigation system may not be enough to fully protect our plantings. The proper application of water, fertilizer and mulch should be just part of a coordinated program to protect our growing herbaceous and woody ornamentals.
This year, we experienced a warm March which forced many shrubs and trees to push new growth much earlier than normal. The following frosts and freezes damaged or killed the tender new growth. June was very dry, July set record high temperatures and August arrived with a series of damaging storms causing cracks and breaks which allow entry for pests and diseases.
Even before your garden grows, you affect the health of your plants. Quality topsoil and proper plant spacing provide long-term benefits. Effective plant placement ensures that they are oriented to receive the correct level of exposure or protection and that they will comfortably adapt to their new setting.
Regular hand watering is essential in the summer if you don’t have an automatic irrigation system. If you do, ensure that your system is well maintained and don’t assume that everything is properly watered unless you actually see it operating. Set your zones to reflect the different micro-climates on your property and adjust the timing incrementally as the weather demands.
Fertilize plants in early spring based on soil tests and the type and size of plant. Fertilizer can seriously harm plants if it’s not the right type or not applied at the right time and in the correct amounts. Nitrogen should never be added in the late fall as it may cause new soft growth which is easily damaged by cold weather.
Mulching is one of the best ways to maintain healthy landscape plants. Regular replenishment of hardwood double-shredded mulch affords many benefits; it retains moisture, suppresses weeds, releases nutrients, protects against compaction and insulates the soil from temperature extremes. Mulches that do not offer all these advantages include; wood chips, pine bark and inorganic mulches such as pea gravel.
As we indicated in our earlier Integrated Pest Management (IPM) post, insect pests may be the number one cause of disease spreading among plants. Good insect control is really the key to preventing many disease related problems. Insect screens and timed sprays including dormant oil and anti-desiccant can be a life-saver.
Careful and regular inspections of your plants can prevent a minor problem from becoming chronic or fatal. You can detect pests and diseases before they get out of hand. Like preventive medicine for people, IPM systems are customized to avoid problems before they arise, and they save money by limiting chemical treatments.
A clean landscape is fundamental. As important as mulch is, leaving leaf litter, matted grass clippings or broken branches around your plantings invites pests and diseases. Improper pruning can also transmit plant diseases if your tools are not kept clean. Clean up now, avoid headaches later.
A customized, well-informed focus on plant vitality is essential to protect our landscapes from increasing environmental stressors. Applying the variety of preventive techniques currently available is cost-effective and enhances our green world.