Time to Protect Your Plants from Frost

Mark Holt, Community Educator, Agriculture/Horticulture
Cornell University Cooperative Extension of Allegany and Cattaraugus Counties

Historical data from the National Weather Service indicates that many areas of Allegany and Cattaraugus Counties will have their first frost of the season within the next two weeks.  While it’s sad to see the traditional gardening season come to an end, you may be able to extend your gardening season a bit longer with careful attention to the weather forecast and a little extra work to protect tender plants.

Frost forms first in low-lying areas.  Cold air is denser than warm air, so the colder air settles in low-lying areas of your landscape and garden.  Tender plants in these areas need protection to survive frosts.  Sloping areas tend to frost less often, as it is more difficult for the cold air to settle there.

As air cools, moisture condenses out of it and settles as dew.  When the temperature of plant surfaces falls to 32 degrees, dew will freeze and frost will form on the plant.  Frost is more likely to form on cloudless nights without wind.  A cloudy night tends to stay a bit warmer, as hot air is trapped closer to the earth’s surface.

Tender plants such as annuals and warm season vegetables are subject to frost damage.  A heavy (killing) frost can even kill these non-hardy plants.  Frost damage or death occurs when the moisture in the plant cells freezes and damages the cell walls.  When the plant thaws, the damaged cells lose their ability to support the plant and transport water and nutrients.

Frost can occur even when the air temperature is above freezing, due to cold air settling, microclimate variations, and other factors.  Many frosts occur when the air temperature is in the mid-30s.  The extent of damage to your plants will depend on the type and hardiness of the plant, the maturity of the plant (older plant tissue is less subject to freeze damage than newer tissue), duration of the frost, and other factors.

To protect from frost damage, cover your plants.  If plants are in containers, move them into a protected area or indoors.  You can cover individual plants or a whole row of plants with burlap, bed sheets, plastic sheets, milk jugs, inverted flower pots, or anything else that will preserve stored heat and prevent dew from settling on the plants.  Protective sheeting material is most effective when supported above the plants by some sort of a frame or even individual stakes.  But if necessary, it can be laid directly on the plants and still provide some protection.  Even the spun polyester “floating row covers” available at garden centers can offer 4-5 degrees of protection against freezing temperatures and frost.

Remember to cover your plants before nightfall, as much of the stored heat from the day will be lost by dusk.  After the frost has melted in the morning, remove the covers so the plants don’t overheat.   You can collect extra heat during the day by painting empty milk jugs black and filling them with water.  Place them near the plants in your garden.  The jugs will slowly radiate heat during the night under the protective cover.

Container plants are particularly susceptible to frost damage because their root systems are limited and the above-ground container is exposed to rapidly fluctuating air temperatures.  Move container plants indoors or into a protected area, or sink the container into the ground, or wrap both the plant and the container in burlap to protect from freezing temperatures.

Further information on this and other gardening topics is available from Cornell Cooperative Extension Master Gardener Volunteers in Allegany and Cattaraugus Counties.  Contact a Master Gardener by telephone or e-mail:

Allegany County:  (585) 268-7644 x23, e-mail:  alleganymg@cornell.edu

Cattaraugus County: (716) 699-2377 x127, e-mail:  cattaraugusmg@cornell.edu

Fall Gardening Chores

By Lyn Chimera, Cornell University Cooperative Extension Master Gardener

Fall weather is here, whether the calendar says fall or not. The nights are delightfully cool and some trees are changing. These changes remind us that it’s time for end of the season chores. The following are some tips on what can be done mid to late September: 

- Since the nights are getting into and below the 50’s it’s time to start bringing in any houseplants you had outside for the summer. First closely examine them for any insects, disease etc. and remove old and ratty leaves. Give them a good water bath with a soft sponge and let the water run through the soil as well. Rinse very thoroughly.  It’s best to acclimate the plants slowly so the temperature and humidity change isn’t such a shock. This is best done BEFORE you put the furnace on.

- It’s also time to take in any annuals you want to winter over. Follow the same procedures as mentioned above.

- If you’re taking cuttings to propagate you follow the same procedures. Cuttings can be started in a vase of water or directly in potting soil. If started in water it’s important to plant them in soil shortly after the roots start to develop. If starting in soil, rooting hormone can be helpful. Keep the cuttings moist but not wet.

- Good garden clean-up is essential to help prevent disease next season. Carefully remove and discard any leaves & stems of infected plants and remove.  Do NOT compost any diseased plant material unless your compost gets hot enough and sustains this heat long enough to kill diseased materials.

- It’s not necessary to cut back all the perennials. Leaving plants with seed heads intact is good food for winter birds. The crowns and leaves of the plants also serve as a protective cover for the plants against temperature changes during the winter.

- Cut back plants, like hosta, which have leaves that turn soft and mushy. If you leave up the hosta blossom stems you’ll know where that plant is next spring as the stems stay stiff all winter.

- Contrary to popular belief, fall is not the best time for pruning trees, shrubs and roses. Late winter and early spring are best. The exception being spring blooming shrubs like lilac and forsythia. Those should be pruned after they bloom next spring.

- If you fertilize your lawn the best time to fertilize is between Halloween and Thanksgiving.  It is still possible to over seed small areas but the nights are getting colder so I wouldn’t wait much longer.

- Now is a great time to move and divide perennials, especially ones that bloom in spring. If we don’t get much rain be sure to keep them well hydrated.

- It’s also a good time to plant trees and shrubs. Many nurseries are having sales and there are great deals to be had. However, examine the plants carefully. An unhealthy plant is not such a bargain.

One chore at a time and you will be ready before the first real snow storm!

Cattaraugus County Master Gardeners Present “Fall Gardening Day”

Do you want to learn how to protect your garden over the winter?  Do you want to enjoy spring flowering bulbs next April?  Then come and enjoy the programs of the Cornell University Cooperative Extension Master Gardeners in Cattaraugus County for “Fall Gardening Day”.  This fall gardening program is appropriate for interested gardeners of all levels of experience, and will focus on the theme “Putting Your Garden to Bed”.

Fall Gardening Day will be held on Saturday, September 27, 2014 from 9:00 am to 1:00 pm at the Ellicottville Town Center / Cooperative Extension Center, 28 Parkside Drive, Ellicottville, NY 14731.  Pre-registration is required (see details below).  Topics will include fall soil testing and improvement, cover crops, fall lawn care, fall blooming perennials, garlic, rhubarb, spring flowering bulbs, and extending your growing into late fall and winter.

Registration is $5 and includes a soil pH test (bring an air-dried soil sample) and tool sharpening (bring a tool to have sharpened). To register or for more information, contact Marilyn Gold at Cornell University Cooperative Extension at 716-699-2377 x106, or by e-mail: cattaraugusmg@cornell.edu

Cornell Cooperative Extension provides equal program and employment opportunities. Accommodations for persons with disabilities may be requested by calling the Ellicottville office at (716) 699-2377 x106.

Secrets of a Happy Wintergreen Plant

By Mary Lu Wells, Cornell University Cooperative Extension Master Gardener

This is a tale of the little plant that couldn’t. Eight or so years ago, I bought a small wintergreen plant from a good nursery. This wild ground cover from N.E. forests loves the humus rich, acidic soil found in the shade of our deciduous forests. I assumed acid meant a pH of 6 or so and that our Allegany County soil would be perfect since are native soils are mid to high 5.0’s.

wintergreen plantThe wintergreen was planted on the north side of my house with my other woodland wildflowers. There it sat, neither dying nor growing. Wintergreen is a lovely ground cover growing 4-6 inches tall with small shiny evergreen leaves. In June, the small very pale pink bell flowers appear to be followed in late summer by scarlet berries. Both leaves and berries make a delicious wintergreen tea.

The mystery of ‘survive but not flourish’ was solved when I researched this plant in a wild flower book.  Wintergreen’s do need an acidic soil as I thought, but not 6 it wanted 4.5-5! This is very acidic, think blueberries. So I bought some pure sulfur and added it to the soil in the fall. This I now do every October according to my soil pH test, then mulch with pine needles. Amazing! My little plant that couldn’t now covers a square yard and blooms heavily.

The moral of this story: never assume, always check your facts. Supply what your plant needs and they will respond. So, if you covet blueberries, holly, azaleas, FIRST test your soil! Cornell has been hosting free pH clinics throughout the county from August till the end of September. Pick one of our remaining clinics to get your soil tested. Limit of 2 samples per resident.

Sept. 11th: 11 am – 1 pm  Belmont – Farmers Market, MG’s Carol Sitarski, Brenda Starr
Sept. 20th: 10 am – 12 pm  Scio – Riverside Sales & Service, MG Susan Duke
Sept. 27th : 11 am – 1 pm  Alfred – Tinkertown Hardware, MG’s Mary Lu Wells, Mary Harris

Photo: http://plants.ces.ncsu.edu/plants/all/gaultheria-procumbens/

Allegany County Farmer Neighbor Dinner & Taste of Local Farms

Allegany County Cornell Cooperative Extension, Soil & Water Conservation District, Natural Resource Conservation Service & Farm Service Agency invite you to attend the Allegany County Farmer Neighbor Dinner on Wednesday, September 24, 2014. The event will be held at the Amity Rescue Squad Hall, 5184 State Route 244 in Belmont, NY.

The Farmer Neighbor Dinner is an opportunity for farmers, members of the community, local leaders and friends to come together to recognize and celebrate the tremendous role that agriculture plays in Allegany County. We will open at 5:30 PM with a Taste of Local Farms & Exhibits.

Come join us and enjoy the many faces of agriculture represented from throughout the county. Sample local products as appetizers before enjoying an expertly catered meal prepared from food produced in Allegany County. Taste the difference, try something new and meet your farm neighbors. Celebrate the Diversity of Agriculture in Our County.

Dinner tickets are $25 per person. Pre-registration is due by September 12th. For more information or to register, please contact Lynn Bliven, Agriculture Issue Leader at 585-268-7644 ext. 18, or by email lao3@cornell.edu.