SPECIALTY SUMMER SQUASHES

Members of the species Cucubita pepo

A member of the Gourd Family

The summer squashes are native to tropical and temperate America and have been cultivated since before the arrival of Columbus. There are a wide variety of commercially available varieties of the various types of summer squash. The fruits of summer squash are usually eaten at the immature stage. The plants have either a compact form or have long runners. The male and female flowers occur separately on the same plant. Summer squashes are grown extensively in gardens and in commercial fields in the United States. There has been an increase in interest in unusual types of summer squash in the market and many of those varieties are described here.

Summer squash is sold in 28 pound boxes and the price can fluctuate widely during the season depending upon the supply and demand. In California the early season production begins in the desert in February and then moves to the Fresno-Tulare area where production begins in April under plastic tunnels to protect the crop from the late frosts. Production continues through mid to late October after which time imports from Mexico provide the squash supply through the winter months.

Summer squashes are warm season vegetables that come into production 6 to 8 weeks after seeding. They are not frost tolerant and the optimal temperatures for growth are between 65 to 75 F.

Summer squashes are primarily direct seeded, after to danger of frost is past, into warm soils above 60 F but some growers use transplants in order to get an earlier start or avoid the risk of having the seed rot in cold soil. Plants are grown on 40 or 60 inch beds and are spaced 12 to 30 inches apart depending upon the growth habit of the variety and the row spacing.

The summer squashes are irrigated with furrow, sprinkler or drip irrigation. The high humidity of sprinkler irrigation can aggravate problems with powdery mildew and scab (Cladosporium cucumerium) and protective fungicides are applied to reduce these diseases.

In general, summer squashes only require 60 to 120 pounds of nitrogen per acre for good crop growth. Irrigation water must be applied with sufficient frequency to never allow the crop to suffer water stress. This is especially true during the harvest period because a lack of water can cause fruit distortion.

Summer squash is a labor intensive crop that requires harvesting every 2 to 3 days. As a result, fresh market squash is frequently grown in areas with many small-scale producers that have access to a readily available labor supply.

Aphids are a serious problem on summer squash. They can attack the growing point of the plant and deposit honey dew on the fruit.

Zucchini - Zucchini is the most popular of the summer squashes. In California the shippers prefer dark green varieties with a straight, cylindrical shape. Common varieties of this type include 'Ambassador' and 'Onyx'. There are other green zucchini types that have other characteristics such as spineless petioles ('Spineless Beauty') or a round shape ('Gourmet Globe'). There are a number varieties such as 'Gold Rush' and 'Goldfinger' which are yellow zucchini types. 'Cocozelle' is an Italian type of zucchini that has strong ribbing and dark green alternating with light green stripes. 'Vegetable Marrow Bush' is a very pale green color and is a favorite variety of the British. Cousa types are pale green that taper towards the stem end of the fruit are a popular fruit in middle eastern cuisine.

Yellow Summer Squashes - The squashes in this category are also called yellow squashes and are commonly thought of as the crooknecked squashes. The common varieties utilized are 'Dixie' and 'Sundance'. There are differences in the amount of crook that occurs in the neck and as a result there are semi-crookneck types (ie 'Supersett') and straight neck types (ie 'Gold Slice').

The fruit of the yellow squashes are susceptible to getting green streaks on the them if the plant becomes infected with virus. Varieties that possess the precocious yellow gene such as 'Supersett' will tend to retain their normal yellow color inspite of infection with virus..

Some growers pick the squash in this group as miniatures with the flowers on the fruit and market them as a specialty or gourmet item. Varieties that possess the precocious yellow gene have a bright yellow fruit even when the fruit is very small and as a result, they lend themselves very well for use as baby squash.

Seed companies have recently been breeding for various shapes in these varieties. One recent release is the variety 'Sun Drops' which has a miniature oval shaped fruit. It is occasionally marketed at farmer's markets.

Scallop - These squashes are also known as patty pan or summer squash. The common varieties have the characteristic flattened shape and are light green in color (ie 'Bennings Green Tint'). The variety 'Scallopini' is a scallop type that has a dark green zucchini color. 'Sunburst' has a bright yellow color with a green blossom end and is frequently sold as a miniature. The variety 'White Ruffles' has a white-green color. The seed companies are developing scallop types that are longer rather than flattened and these novel types should soon be available.

Winter Squash Types - There are areas of the country and of the world where people eat winter squashes in their immature state. Some winter squashes have similar textural characteristics of the summer squashes when they are eaten in this way. There are a number of varieties that are eaten in the immature state; 'All Season Buttercup' and 'Table Gold Acorn' are two varieties that are worthy of note.

Written by Richard Smith, Farm Advisor, San Benito County