Melons are members of the cucurbit family,
which includes pumpkins, zucchini, cucumbers, summer squash and winter squash.
Being closely related, melons have similar growth requirements, however they
will not cross-pollinate with cucumbers, squash or pumpkins.
Melon quality is a function of the sugar
content of the fruit. High sugar content is achieved by avoiding all stress
during the growing season. Stress comes from foliar diseases, insect pests,
weeds, poor nutrition, and excesses or lack of water.
Melons prefer hot, sunny locations with
fertile, well drained soils, and can be either transplanted or direct seeded.
Transplanting can add 2 to 4 weeks to the growing season, but melons are
particularly sensitive to root disturbance and growth will be retarded if
transplants are not properly managed.
Seeding
Melon seeds germinate optimally between 70
and 90 degrees F but can be sown when the soil temperature is above 65 degrees
F. Planting in cooler soil favors soil borne root diseases which can decimate
or stunt melons which are cold intolerant. An average planting date is a week
to 10 days before the historic frost free date. This is approximately May 20 in
Minnesota but will vary depending on your latitude.
Plant the seeds ½ to 1 inch deep. Plant 2 to
3 seeds in groups 18 to 24 inches apart within the row and later thin to the
best plant per group. Space rows 5 to 6 feet apart.
Transplanting
Sow seed indoors at the end of April, about 2
to 4 weeks prior to the transplant date. Transplants should have 2-3 mature
leaves and a well developed root system when they are moved into the garden.
Plant the seeds in peat pots or other biodegradable containers that can be
placed directly into garden soils. This will help avoid root disturbance and
damage. Damaged roots in seedling transplants slow establishment and growth.
Plant the potted seedlings 2 feet apart through plastic mulch for early
maturity.
The use of plastic tunnels and fabric covers
can protect seedlings and transplants from cool air temperatures and early
insect pests. Covers can increase temperature around the plant and will stop
pollinating insects from reaching the flowers. Remove covers once fear of frost
has passed to avoid high temperature plant injury and to allow bees and other
pollinators easy access to the flowers.
Cantaloupe plants can be grown in small
gardens by training the plant to a fence or trellis. After the fruits begin to enlarge they will need
support or the fruit weight may damage the vines!
Soil pH and fertility
Muskmelons grow best on well-drained, sandy
loam soils with a pH level between 6.0 and 6.5. Soils with a pH less than 6.0
will produce plants with yellowed foliage and fewer perfect flowers. If
drainage is a problem, plant in 6 to 8 inch high beds. Before adding any
compost, manure, or fertilizer, have your soil tested (see Understanding Your Soil Test Report) to determine your soil’s pH and whether it
should be amended.
You can also improve both heavy clay soils
and lighter sandy soils by adding organic matter. Addition of manure or compost
is beneficial for vine crops and improves soil structure. Plow or till
well-rotted manure and fertilizer into the soil before planting. If you use
manure or compost, additional fertilizer applications may be reduced or
eliminated, depending on how much organic matter you apply. Do not use “Weed
and Feed” type fertilizers on vegetables. They contain weed killers that will
kill vegetable plants.
Timely and appropriate applications of
fertilizer can make a significant difference in the quality and quantity of
fruit and may promote earlier harvests.
Mulches
Plastic mulch warms the soil, conserves
water, helps to control weeds, allows earlier planting and maturity, and
reduces ground rot of the fruit. The use of transplants with plastic mulch
generally results in harvests that begin 7 to 14 days earlier as compared to
growing melons on bare ground. To get the benefits of plastic mulch, proper
installation is critical. First lay drip irrigation or a soaker hose on the
soil. Be sure to offset the drip tape 2 to 3 inches from the center of the bed.
Further maximize the benefits of plastic mulch by installing it over raised
beds. Lay the plastic mulch during the hottest part of the day and make sure
that the mulch is stretched tight over the soil without any wrinkles. Lay the
plastic, secure the edges with soil on each side of the raised bed, and cut
holes for the seeds or transplants. When using plastic mulches and row covers,
seeds or plants can be set out about 2 weeks before the last frost date.
Organic mulches like woodchips or straw can
also be used when growing melons, but do not apply organic mulches until soils
are warmer than 75°F.
Controlling weeds
Frequent, shallow cultivation will kill weeds
before they become a problem. The roots of melons are close to the surface of
the soil, so it is important not to cultivate too deeply or too close to the
plants. Cultivate just deeply enough to cut the weeds off below the surface of
the soil. Continue cultivating as long as you can do so without injuring the
vines, usually when the vines begin to spread between the rows. When
cultivation is no longer possible, pull large weeds by hand.
Watering
Water deeply and infrequently, 1-2 inches per
week. Use drip irrigation if possible. Mulch around the plant will conserve
soil moisture and reduce weed growth. Always soak the soil thoroughly when
watering. There is little or no value in a light watering that only wets the surface
of the soil. Reduce watering amount as the fruits ripen to improve flavor. Even
watering is extremely important especially in the last 2 weeks of growth.
Excessive watering at this stage can cause the fruits to split.
Pollination and flower types
Cucumbers, squash, pumpkin and watermelon
have separate male and female flowers. Cantaloupe (muskmelon) has two flower
types, male flowers and complete flowers (having both male and female parts).
Cantaloupe flowers have a pollination window of one day. Pollen must be
transferred from the male flower to the female flower on this day for seed set
and fruit development. Fruit size and shape are related to the number of seeds
set. Poorly pollinated flowers either abort or produce misshapen fruit.
Harvest and storage
Harvest and storage
Cantaloupe requires 35-45 days to mature from
flowering, depending on the temperature. As the fruit matures the skin surface
netting gets coarse and rough, the background color of the fruit turns from
green to yellow,the surface color becomes dull, and the tendrils near the fruit
(which look like curly strings) on the stem dry and turn brown.
Harvest the fruits by twisting the fruit at
which point it will separate from the vine. Do not wait for the melons to
separate from the vine on their own. At full maturity and peak flavor the stem
breaks (slips) away from the vine easily. This stage is called “full slip.”
Commercial melons are harvested at "1/2 to 3/4 slip" to reduce
shipping damage. This removes the fruit before it has reached maximum sugar
content, and sugar content will not increase after harvest. This opportunity to
harvest at maximum ripeness is one of the advantages of growing your own
melons. Pick melons as they ripen as they will not all ripen at the same time.
Cantaloupe will store for 1-2 weeks if held at 45-50°F.
Identifying ripe watermelon and honeydew
melons is more difficult as most of these fruit types do not slip from the
vine. Use a combination of indicators to determine ripeness. Look for (1).
tendrils near the fruit stem to become brown and dry; (2) the fruit surface to
become rough to the touch and the fruit color to become dull; (3) the bottom of
the watermelon (where it lies on the soil) to change from a light green to a
yellowish color. Assuring ripe honeydew melons can be achieved by placing the
melon in a bag with ripening apples or tomatoes. The latter will release
ethylene gas which will complete the ripening process.
Select melon varieties that will ripen under
your conditions. Short season types ripen between 65 and 75 days. Full season
types ripen around 85 days.
Common problems
Environmental
Environmental
Poor fruit set could be due to improper
pollination, very hot weather or water stress. Pollination may be hindered by
cold rain and cloudy weather.
Tasteless melons could be due to dark, cloudy
weather, or disease.
The first blossoms often drop off muskmelon
plants but this is not a problem. The first flowers to appear on the vines are
male. The female flowers, which open later, have a swelling at the base that
forms the fruit (the ovary). After bees pollinate these female flowers, the
fruit develops!
Insect
There are a few insects that occasionally
attack melons. Squash bugs feed on foliage and can harm young plants. Squash vine borers can kill plants as they tunnel through the
vines. Wilting vines will probably be the first symptoms you will notice. Striped cucumber beetles damage plants by eating leaves as well as
stems and fruit. They are also a potential vector of bacterial wilt.
Disease
Melon seedlings are susceptible to damping off especially when planted into cold wet soils.
In some years bacterial wilt can cause wilt and decline of cucumber
plants. Powdery mildew, a fungal disease that causes powdery white spots to
form on leaves and vines can infect melons. Look for resistant varieties if
this disease has been a problem in the past. Several fungal leaf spot and fruit
rot diseases can affect melons. Damage can include brown spots, tattered holes
in leaves, sunken brown lesions on vines, and rotted fruit. To avoid these
diseases do not grow melons in an area where any member of the squash family
has been grown for 3-4 years. Reduce moisture on leaves by providing plants
with proper space, controlling weeds, and using drip irrigation or soaker hose
instead of sprinkler irrigation. Remove severely infected plants from the
garden. At the end of the season, till in plant residue or remove plant debris
if infection was severe.