Who doesn’t want to keep there sunshine of plants protected in winter months? I have solutions for the Southeastern United States. As fall is upon us, plants are preparing for dormancy. You may think all activity in the garden has stopped. There is a lot going on under the soil until it freezes. It’s capturing soil nutrients and moisture.
Most plants explode in the spring, growth slows in fall because of shorter days and cooler temperatures. To grow plants faster we fertilize and irrigate. To choose the right way to prepare you have to understand how they are damaged by the cold.
Dormancy is suspension of plant growth. Plants may stop growth or appear dormant. High temps and draught can do this and send a plant to go into dormancy. If nurtured with water and as temperatures decrease, growth resumes. At fall growth starts to slow down. Vegetable and flower buds are formed for the next year. Fall practices as applying fertilizer, pruning, and protection are vital. Failure to provide these can result in injury or death during winter of your plants.
Fall frost makes the plants start to become dormant. As dormancy continues, plants begin energy storage and leaf coloration. During winter, plants acquire hardiness.
Location of plants also effects winters hardiness. Species from southern areas in the US get cold weather later in the year and develop less mid winter hardiness. In the southeastern US, moist warm falls are common. Some areas don’t receive their first frost till late November. Unfortunately temperature can favor growth in these areas even to the last frost. Plants can become injured if not protected during this time.
The use of nutrient control with winter hardiness is critical. You can oversupply or cause deficiency. This is something you must take into consideration. If using liquid fertilizers stop about six weeks before first frost date.
Most people usually plant in pots in spring. Growers also have to pot plants year around depending on species of plant. If you pot in fall you should reduce fertilizer to prevent injury. If you want to apply fertilizer in the fall wait until aboveground ground plants are dormant. Fertilization will prevent early growth and decrease nutrients being released early.
The part of the plant that enters the soil is the last to have full winter hardiness. Plants that receive very dry weather during the fall are less able to handle severe winter conditions. Drought in the fall leads to the reduce of storage of nutrients, plants may not get enough stored energy to bud break.
Watching volume of irrigation is one away you can control the plants. A .10 leaching fraction is important. Leaching is determined after the irrigation has ended for the day. Collect and measure the amount of water in each bucket. The water in C1 bucket is total volume applied and amount in C2 bucket is amount leached. C2 divided by C1 equals the leaching fraction. This is a easy way to see whether the volume intended is actually being applied.
Plants do need water from time to time in the winter, as water freezes it gives off heat that can be captured. Watering plants before a freezing will allow it to store water.
Do not prune within six weeks of first frost. Late fall pruning is not recommended it can create wounds. These wounds do not close until growth starts in spring, making it easier for decaying organisms to begin in the wounds.
Plants lose moisture through leaves first and very fast. They are drying out. Very windy areas and cold yet sunny days with little bit of wind can cause severe desiccation. Wind injury can be fatal. if the soil freezes, no moisture is there for leaves. The plants can’t be killed by wind.
When selecting where you want to put the plant, seek out an area with coverage that reduces plant damage in winter. Avoid area with excessive wind, frost pockets and abnormal early warming in spring or fall months.
Wind barriers can prevent windburn. Large trees, bushes can help with windburn, windbreak blocks wind and raisies it upward. Moving upward reduces air movement across plants.
Light duration can affect plant dormancy. Plants grow slower in shade. Growers remove shade in September to harden the plants and reduce splitting. Removing shade from active plants may cause sun scald. You can remove shade to increase hardiness during the short period after new growth has hardened but before the cold has kicked in.
Apply mulch after plants have hardened. Mulching before initial frosts insulates the plants. In the southeastern this is after November 15th.
If temperatures have been below 50* F for many days after August first,then plants probably will be able to flourish in the extended cold. If temperatures are above 68* F for many days than plants may not be as strong and require extra coverage.
Ways to protect plants
*water citrus and avocado trees to prevent fruit splitting
*stop feeding tropical trees in September
*use straw bales to protect from wind
*mulch in and all around plants using newspaper, hay or composted material
Place double layer of white poly on house with a inflator fan. Place an independent heat source in house. That can be portable forced air heater that runs off fuel or electricity. Permanent propane, electric, or wood fired heater can also be used.
Taking these steps can save your plants in the months coming up. Insures you another year of beautiful plants and hopefully many more to come.
Dunwell, W. and R. McNeill overwintering nursery crops. accessed october 6, 2009 http://www.ca.uky.edu/HLA/Dunwell/ovrwtr9.html
Ivy,R L., T. E. Bilderback and s. l. Warren. 2002. Date of potting and fertilization affects plant growth, mineral content, and substrate electrical conductivity. J. Environ Hort, 20:104-109
Clemson Unv. Agricultural Service laboratory. http://www.clemson.edu/public/regulatory/ag_svc_lab/
College of Agriculture & Life Sciences