¶¶̉ờ½̀½

VERMONT VEGETABLE AND BERRY NEWS, November 7, 2007
Compiled by Vern Grubinger, University of Vermont Extension
(802) 257-7967 ext.13
vernon.grubinger@uvm.edu
www.uvm.edu/vtvegandberry
 
DON’T MULCH YOUR STRAWBERRIES PREMATURELY
(adapted from Kevin Iungerman, Cornell Extension, Northeastern NY)
 
Applying mulch prematurely can unwittingly rob your strawberry planting of its maximum edge going into winter. Even though early stage dormancy in strawberries is reached in October, mulching anytime before mid-November can shut down light interception too early, meaning that the plants will have less energy to support their winter acclimation. Since survival over the winter often hinges upon very small differences in energy available to maintain plant health, the negative effects of premature mulching can be quite significant.
 
The latter part of November is generally recommended as the strawberry mulch window in our area. Defer even later, into early December, if weather conditions allow (no snow and the fields are still amenable to tractors, wagons, and equipment. Track the progression of ground temperatures, noting when time where soil temperatures are running at 40°F over several consecutive days. You should apply your mulch prior to the ground freezing.
 
Straw remains the mulching material of choice on strawberries. Wheat, rye, Sudangrass, barley and oat straws work well (and my preference is in the same order). Straws coarser than Sudangrass are not recommended. But clean straw is essential! If your primary criterion is the price per bale, then you are inviting trouble! If possible, examine the straw for its grain or weed seed contamination before you buy it, and certainly before you apply it! Don't import headaches that might largely be avoided with just a little extra care. If need be, it is preferable to grow it yourself or to have it contract-grown so that you can closely control or monitor its cutting time. (Cut before the seed is viable!) It is no bargain to use seed-contaminated straw, as you will surely pay for the hidden extras in herbicides, cultivation, labor and headache.
 
There are plenty of reasons to mulch strawberries adequately. Unprotected strawberry plants are very vulnerable to desiccation from exposure to drying winter winds. Don’t skimp. Cold can do considerable mortal damage. Crowns reportedly kill when their plant cells reach temperatures of about 7°F to 10 °F. Traditional level matted row plantings will require 2.5 to 3 tons of straw per acre, for a 2-3 inch deep mulch (about 300 small bales of average weight). Raised bed plantings have greater vulnerability as they can be several degrees colder than flat beds because they have greater soil surface area exposed to radiant cooling. In spring you take advantage of the same principle but to reverse effect: greater warming. Consequently, add more straw to raised beds - perhaps twice the amount for adequate coverage (4-5 tons). The same might be done on less hardy cultivars or in windier locations. Remember to maintain a reserve of bales in a dry, freeze-free location so they are available for immediate replacement of straw that blows off during the winter. Monitor coverage often, especially if snow cover is light and it’s windy.
 
WHAT'S NEW IN FALL RASPBERRIES
by Pam Fisher, Ontario Ministry of Agriculture.
 
The fall raspberry scene has progressed far beyond Heritage - which is a great berry, but too late for many Ontario (and Vermont) growers. Here are some other fall-bearing varieties of interest:

• Anne (Univ. Maryland) - This variety is yellow, sometimes greenish-yellow, with no pink or amber tinges. Produces large, conic, pale yellow fruit that ripen mid- to late- season. It has very good flavor and texture. Tall upright canes sucker sparsely requiring higher planting density. It is resistant to Phytophthora root rot but susceptible to leaf hoppers and rust.

• Autumn Bliss (England, 1984) - Early, approximately 10 days earlier than Heritage. Large, flavorful fruit with large druplets. Most of the yield is harvested in the first two weeks of harvest. Somewhat soft. May be crumbly and dark.

• Autumn Britten (England, 1995) – A sibling of Autumn Bliss, Autumn Britten is the Ontario standard. It is more regular in shape and less crumbly than Autumn Bliss. Requires planting at closer spacings because it does not produce an abundance of canes.

• Caroline (USDA Maryland, 1999) – Excellent yield potential, berry size and fruit quality. Yields about 1 week earlier than Heritage, but too late for most regions in Ontario. Susceptible to late leaf rust, but has moderate to good resistance to Phyophthora.

• Polana (Poland, 1991) - Approximately 2 weeks earlier than Heritage and slightly ahead of Autumn Britten. Early, fall bearing. High yields because buds produce 2 fruiting laterals each. Medium sized fruit of good quality. Susceptible to Phytophthora and verticillium.
 
The following varieties are newer and being trialed in Ontario:

• Himbo Top (Switzerland) produces good quality, large fruit on primocanes. The fruit is bright red with good flavor. Plants are vigorous and upright and medium in height that will benefit from trellising. Reported to be resistant to Phytophthora root rot.

• Jaclyn (Univ. of Maryland) is an early season variety with large firm berries ripening 2 weeks before Heritage. Plants are vigorous and erect but susceptible to yellow leaf rust. Fruit is dark red and adheres tightly until fully ripe.

• Joan J (United Kingdom) Good quality firm fruit with small drupelets and good flavor. The fruit will hold and ship well, as it is dry. Considered early.

 • Josephine (Univ. of Maryland) Fruit is large with average flavor ripening mid-season. Berries are firm and cohesive. Plants are upright and vigorous needing little containment trellising. It is resistant to leaf hopper and Phytophthora root rot.

• Polka (Poland) has medium large primocane fruit that ripen in the early season. Widely grown in Europe, it is reported to have good fruit quality and good yields.
 
COMING EVENTS
(for more info see www.uvm.edu/vtvegandberry click on meetings)
 
Nov. 10. Greenhouses and Season Extension for Beginning Farmers. Montpelier VT. Call the ¶¶̉ờ½̀½ Center for Sustainable Agriculture, 802-656-5459.
 
Nov. 13. Greenhouse Tomato Conference. Sturbridge, MA. Topics include choosing varieties, nutrient management, managing plant vigor, using biological control, a hands-on grafting session, disease ID and management, tomato plant disorders and a grower panel on growing and marketing. 3 pesticide credits. $35 includes lunch. Tina Smith, UMass, 413-545-5306 or tsmith@umext.umass.edu

Dec. 3-4. Renewable Fuel On-Farm: Canola, Biodiesel, and Corn. Bangor, ME. Peter Sexton, UMaine Extension,
207-764-3361 or psexton@umext.maine.edu  
 
Dec. 11-13. New England Vegetable and Fruit Conference and Trade Show. Manchester NH.
or call me for a brochure 802-257-7967 x13.
 
Jan. 25-27, 2008. NOFA-NY Winter Conference, Saratoga Springs NY. Over 90 workshops for organic farmers, gardeners.  or  607-652-6632. Early registration deadline is Nov. 30.
 
Feb. 16-17, Randolph VT at Vermont Technical College. NOFA-VT Winter Conference. 802-434-4122 or olga@madriver.com
 
Feb. 25, Capital Plaza Hotel, Montpelier. VT Vegetable and Berry Growers Meeting.
Stay tuned for details…

RETURN TO VERMONT VEGETABLE AND BERRY PAGE