Alaska Pioneer Fruit Growers Association

DETERMINING FRUIT RIPENING DATES

February 9, 1993

By Bob Purvis

 

“Can variety A ripen its fruit before the onset of winter?” A cultivar’s ripening date is an important consideration, next only to winter hardiness for selecting fruit varieties to be grown in a climate with a short, cool growing season. During my tenure (1984-1989) as president of the Alaska Pioneer Fruit Growers (“APFG”), I made field observations of various apple cultivars and their ripening dates and formed this into a table giving a sequence of ripening for 53 apple, applecrab, and crabapple cultivars. One of the members of the APFG recently asked me how I did this, and the purpose of this article is to outline my methodology.

 

To compile such a table would be easy if all the varieties in the table were represented by mature trees growing at a research facility, instead, the situation was that of having to take observations of a few cultivars ripening in diverse locations and to compensate for differences in microclimate.

 

The first step was to get information on ripening dates for some commonly grown Malus (apple, applecrab, and crabapple) cultivars. In the Lower 48, that would be Red Delicious, or possibly Golden Delicious or McIntosh. In Alaska, Yellow Transparent is probably the most commonly grown apple south of the Alaska Range. Norland, Rescue, and Chinese Golden Early are also well represented by bearing trees. State Fair and Summerred mark the end of the ripening season for apples both in Anchorage and the Matanuska Valley, and are also known and grown in Washington, Minnesota, New York, and Michigan.

 

Two (2) Canadian publications were invaluable for tying-the Canadian cultivars’ ripening dates into those of the aforementioned apples. Agriculture Canada Publication No. 1672/E, Tree Fruits for the Prairie Provinces, and John G.N. Davidson3s Apple Varieties Hardy in the Peace River Region, published by the Fruit Growers’ Society of Alberta, both give approximate ripening dates for each cultivar described. Some of these have been grown in the prairie provinces, at Beaveriodge (Alberta), and in southcentral Alaska. For example, in the prairie provinces, Westland ripens in late August; at Beaveriodge, in early September; and in the Matanuska Valley, around September 18. One can therefore use as a rule of thumb that a given cultivar of apple will ripen about two (2) weeks later in Anchorage than in Beaveriodge, or three (3) weeks later in Anchorage than in a typical prairie province location. Norland bears this out: it ripens in mid-August in the prairie provinces and should, therefore, ripen in early September (three [3] weeks later) in Anchorage- and this is indeed the case.

 

This rule was applied to project ripening dates from these two (2) publications into the Apple and Crabapple Variety Ripening Sequence for Anchorage, and in many instances I was able to confirm these dates with field observations. This rule can further be applied to nursery catalogs, such as that of Newark Nurseries, which lists ripening dates for fruit cultivars in southwest Michigan, or to field observations made at Whitney’s Orchard and Nursery on the Naches Heights above Yakima, Washington. Other sources of ripening dates include Publication No. 430, Fruit Cuitivars—A Guide for Commercial Growers, published by the Ontario Ministry of Agriculture and Food; Washington State Cooperative Extension Service Publication No. EB143S, Apple Cultivars for Puget Sound, and the annual catalog, New and Noteworthy Fruits, published by the New York State Fruit Testing Cooperative Association.

 

One question that is sometimes asked is, “Do apples take a lot longer to mature in Anchorage’s cool climate than in a warmer location?” At ????, April 26 is about midbloom for the average apple cultivar. In Anchorage, the corresponding date is about June 8, about six to seven (6-7) weeks later. However, Norland and Chinese Golden Early typically ripen about six to seven (6- 7) weeks later in Anchorage than at Whitney’s, so It appears that the longer summer days in Anchorage largely offset the cooler weather conditions. Thus, if one cultivar ripens three (3) weeks later than another at Whitney’s, it will probably ripen that much later in Anchorage also.

 

It should be emphasized that ripening dates are approximate and are predicated on an “average” summer in an “average” location. Other principles to keep in mind would be that if an apple originates in a climate not noted for abundant sunshine (e.g., that of Geneva, New York, or Scandinavia), it may perform better than expected in Anchorage if its winter-hardiness is adequate. From the nursery catalogs’ ripening dates, it would appear that ripening Jonagold would be hopeless in Anchorage. Yet Lawrence Clark reports that at his south Anchorage location, not far from Turnagain and Knik Arms, Jonagold ripened in 1990 to at least the point of making an excellent cooking apple; this apple originated at Geneva, New York. By contrast, Wealthy, which would ripen before Jonagold according to the Newark Nurseries’ listing, ripens even in the best of years only to being a tolerably good cooking apple. Wealthy originated in Minnesota. Heyer 12, which is from Saskatchewan, likewise develops a better flavor in Fairbanks, which has a more continental climate, than in Anchorage.

 

In closing, if you see an apple cultivar you like in a nursery catalog, the key question to ask is when it ripens relative to Yellow Transparent. If the nurseryman knows first-hand that it ripens less than five (5) weeks after Yellow Transparent, it’s probably worth a try.