Transcript MG15 Cucurbits - University of Maryland Extension

2014-The Year of the
Cucurbits!
Jon Traunfeld, D. Koczaja and N. Tardiff
College of
Agriculture and
Natural Resources
All in the family…
•
•
•
•
•
•
•
Cucumber
Summer squash
Winter squash
Pumpkin
Muskmelon and cantaloupe
Watermelon
Gourds
These are all members of the plant family
Cucurbitaceae and are referred to as
“cucurbits.”
Reasons to grow cucurbits
•
•
•
•
Easy to grow from seed
Lots of different types and cultivars
Some can be stored and eaten over the winter
Versatile in the kitchen
But monitor them closely because they are
susceptible to many insect pests and diseases.
Planting tips
• Full sun location- 6-8 hours of direct sunlight.
• 6-8 in. of loose, fertile soil.
• Plant after Mother’s Day when the soil has
warmed and the danger of frost is passed.
• Cover seedlings with floating row cover to
speed up growth and protect plants from
pests.
• Thin out seedlings so that you end up with the
correct spacing between plants.
Fertilizing tips
• Cucurbits have a moderate need for nutrients
compared to other vegetable crops.
• Add 1 inch of compost each year to contribute to
long-term nutrient reservoir.
• Nitrogen is nutrient most often in short supply.
Fertilize at planting or flowering with one of the
“meals” (kelp, fish, cottonseed, alfalfa.) Or apply
another organic or inorganic fertilizers containing N,
P, and K.
• Over-fertilization can burn plants or stimulate
excessive leaf growth at the expense of fruit.
Sex and the cucurbit
Cucurbit flower structure
Wanted: native bees; must be able to lift and transport
pollen from male to female flowers (we also welcome
European honeybees)
CROP
TYPE OF
FLOWER
OPEN
BLOOM
PERIOD
# OF BEE
VISITS
NEEDED
COMMENTS
Pollination Requirements
Summer squash Imperfect/moneci 6 hrs.; dawn- 8-12
ous
noon
Male flowers open and close
30 min. earlier than female
flowers.
Pumpkin/winter Imperfect/moneci 6 hrs.; dawn- 8-12
squash
ous
noon
Muskmelon
Perfect, self-sterile 8am-dusk
and imperfect
male flowers
12
Stigma receptive to pollen
grains for only a few hrs. early
in morning.
Watermelon
Imperfect/moneci 8am-dusk
ous
8-10
Seedless cultivars require
pollination to set fruit; then
seeds abort.
Cucumber
Imperfect/moneci 8am-dusk
ous
8-12
Male (staminate flowers)
usually appear 10 days before
female (pistillate) flowers
Frequent (but temporary) problems: failure to set fruit and
dropped fruit.
Causes:
•Male and female flowers not open at the same time
•Lack of pollinators due to cold, wet weather, pesticides, and
habitat loss (ovary is not fertilized)
•Plants are over-fertilized, spaced too closely; low sunlight
Deformed fruits- shrunken or
tapered at one end- are caused
by poor pollination; too few bee
visits or failure of pollen to
fertilize ovules (seeds).
Deal with weeds or they will ruin your garden!
Weed management
• Weeds are plants that thrive in disturbed soil.
• Best control methods:
–
–
–
–
crop cover (fast growing cucurbits)
hand-pull
sharp hoe
mulch
• Other organic methods (not recommended): vinegar,
flame weeder, commercial herbicidal soap.
Organic mulches
• Prevent weed growth; add to soil organic matter.
• Moderate soil temperatures; conserve soil
moisture.
• Can provide habitat for pests along with beneficial
critters.
Examples: grass clippings, newspaper covered with
straw, shredded leaves, compost
Synthetic mulches
• Black plastic mulch warms the soil for
earlier, higher yields of warm-season crops,
like melons.
• Landscape fabric warms
the soil and is permeable
to water. Can be re-used.
soil
air
Drip irrigation: saves time and water
Growing up: using vertical space
• Increase yields per sq. ft.
• Fewer fruit problems; easier to pick, water,
and spray.
• Adds complex texture to garden; use
shaded side for lettuce and spinach
Cucumbers
(Cucumus sativus)
• Native of India, cultivated for more than 3000 years
• Slicing or pickling type fruits
– Burpless – thin, more tender skin; milder flavor
• Plant types: bush or vining
– Vining requires trellising
• Days to maturity: 45-65
– Picklers mature more quickly
• Do not do well in clay soils
– Work in 2-3” compost prior to planting
– Fertilize at blossom, and 3 weeks later
GE 108: Cucumbers
18
Cucumbers
• Plant ½” deep, 4” apart in rows 4 feet apart
– Or plant 6 seeds on hills spaced 3 feet apart
– Thin to 6-12” apart in rows, or 3 plants per hill
• Can plant small batches every 2-3 weeks until
late June
• Keep evenly watered, particularly when forming
fruit to prevent bitterness
• Overripe cucumbers become bitter and seedy
19
Melons
(Cucumis melo)
2010
• In Eastern U.S. most cantaloupe are muskmelons
– Rough skin (netting); fruits “slip” from stem
• Honeydew, casaba, crenshaw melon can also be
grown
• Plants seeds 1” deep, 2-3 feet apart in rows 6
feet apart; or in hills spaced 3 feet apart with 3
seeds per hill
• Vigorous vine, not suitable for small gardens,
unless you use a trellis
GE 115: Muskmelon
20
Melons
• For early harvest, start seeds inside 2-3 weeks
prior to transplanting
• Can be hand-pollinated
• Like moist soil and are medium feeders
– Fertilize at fruit formation
• Maturity: 80-100 days; if grown on trellis, the
fruits must be supported
• Harvest when stem separates easily at the
point of attachment
21
‘Minnesota Midget’ above
‘Tigger’ below
Watermelon
(Citrullus lanatus)
• Native of Africa; mature fruits can weigh up to 200 pounds!
• Vine not climbing but takes a lot of ground space!
• Seedless varieties require a seeded variety nearby for
pollination
• Plants seeds 1” deep, 2-3 feet apart in rows 6 feet apart
– Or grow in hills spaced 3 feet apart with 3 seeds per hill
• Seed outside in mid-May
– Can also start indoors 3-4 weeks earlier
• Mature in 76-100 days from seeding
GE 130: Watermelon
2011: this is only 1
23
plant!
Watermelon
• Fertilize when vines begin to run and at 1st fruit set
• Need an inch of water per week at the beginning
– Stop watering when the fruits begin to ripen
• Harvesting:
– Tendrils will turn brown and dry
– Green color is less bright
– Skin will be resistant to thumbnail penetration
– Rind on the underside of the melon will turn from
24
white to pale yellow
Watermelon, Japanese style
Watermelon’s distinctive
lobed leaves
‘Yellow Moon & Stars’, an
heirloom cultivar
Audra Russell, UME
Master Gardener, with
impressive harvest
Summer squash
(Curcubita pepo)
• American natives, known for their abundance
in the backyard garden
– August 8: “National Sneak Zucchini on your
Neighbor’s Porch Day”
• Can be: green (zucchini), yellow (straight or
crookneck), white (scalloped or pattypan)
– Round or oblong varieties
• Large plant: bush or vining
types
GE 125: Summer Squash
27
Summer squash
• In mid-May plant 5-6 seeds in hills 3 feet apart and
thin to 3 plants per hill, or plant 2-3 feet apart in
rows 2-3 feet apart
• Can plant as late as mid-July (Central MD)
• Medium feeders: fertilize 4 weeks after blossoming
• male flowers to appear 1-2 weeks before female
Possible to hand-pollinate for more fruiting
28
Summer squash
• Harvest when fruits are 6-8 inches long
– ‘Baseball bats’ will become spongy and seedy
• Round or scalloped types are best at 3-4”
diameter
• Flowers are edible – great in salads!
• Great in soups, baked, fried
– Also in PIE!!!
29
Yellow straightneck
squash
Zucchini fritters or bread
anyone?
Scallop or patty pan squash
Prevent fruit rot disease by
removing blossoms from
enlarging fruit.
Natural color pattern in
zucchini leaves.
Winter squash/pumpkin
(Curcubita spp.)
• Some are the same species as summer squash (Cucurbita
pepo), but harvested and eaten at mature stage
– Skin toughens into hard, inedible rind
– Great source of beta carotene, Vitamin C, and potassium
• Lots of fun shapes and sizes, including:
Butternut Acorn
Spaghetti
Pumpkin
Gourd
• Vining plants take a lot of space
• Mature in 80-105 days from seed
GE 131: Winter Squash
32
Immature spaghetti squash
Winter squash/pumpkin
• Plant 2-3 seeds every 3-4 feet in rows 8-12
feet apart; can also grow in hills 3-4 feet apart
• Fertilize at planting and again 3 weeks after
blossoming begins
• Can hand-pollinate
• Plant Halloween pumpkin June 15-July15
• Prop pumpkins off ground to
prevent rotting
33
Winter squash/pumpkin
• Harvest when rinds are hard and firm
– Use sharp knife to cut stem, leaving 2” to prolong
storage
• Store winter squash in a cool dry area, like a
basement
– Store in single layer without touching to
discourage rot diseases
• Preparation: peeled, diced, and
roasted; pureed in soups; roast the
seeds!
34
Spaghetti squash above and
butternut squash below.
Cheese pumpkin
So many kinds of winter
squash and pumpkin!
‘Tromboncino’ squash
‘Cucuzzi’ gourd (white flower)
The vines grew up into this
gardener’s trees. Fruit elongate
rapidly and are tender at 4 ft. in
length.
Cherry tomato
Mouse melon
Mouse melon
Organic Integrated Pest Management
(IPM)
• Organic pesticides are a last resort
• Planting to provide nectar and pollen for
beneficial insects (including pollinators )
mountain mint, anise
hyssop, thyme, oregano,
basil, dill, yarrow, aster,
marigold, zinnia,
alyssum, phlox, bee
balm, milkweeds,
butterfly weed, borage,
salvias, lamb’s ear
Biological control
• Give mother nature a chance!
– Predators eat pests
– Parasitoids lay their eggs on or in pests
Natural predators
Orb-weaver spider
Assasin bug
Lady beetle larva
Tiny, non-stinging wasp parasitoid inserting eggs into
aphids. The wasp larvae hatch out and eat the aphids
from the inside.
Floating Row Covers
• First line of defense against frost- spring or fall
• Hastens germination
• Protection for tender plants/seedlings from
heat/sun
• Excludes pests
• ‘Hold-ups’ (support); examples:
pvc pipe, reinforcing wire, and
nine gauge wire
few; be creative!
Floating row cover
supported by #9 wire
above and pvc pipe
below.
Enviromesh protects crops
from insects and wildlife.
Some effective organic insecticides
• Pyrethrins- controls or suppresses a wide
range of insects (Pyganic- 1.4%)
• Neem extract – suppresses beetles and
caterpillars
• Neem oil- insecticide and preventative
fungicide
• Spinosad- controls beetles, caterpillars, flies,
thrips
Some effective organic
insecticides (cont.)
• Bacillus thuringiensis- controls young
caterpillars; suppresses large caterpillars
• Surround- controls aphids, mites, caterpillars;
suppresses bugs
• Hort oil- controls aphids, mites, soft-bodied
immatures
• Insecticidal soap- suppresses aphids, mites,
soft-bodied immatures
Spotted cucumber
beetle
Striped cucumber beetle
All plant parts are affected
Bacterial wilt disease
bacterial ooze
Organic management
• Difficult to hand-pick; must be controlled
early in season.
• Exclude with floating row cover.
• Protect plants prior to flowering with
organic insecticides (apply to both sides of
leaves).
• Seal up badly infested plants in plastic bag.
• Plant late; plant multiple crops.
Squash bug
Squash bug eggs and immatures
Squash bug parasitoid
Organic management
• Remove plant debris to eliminate
overwintering sites.
• Hand-pick adults and eggs; trap with wooden
boards.
• Floating row cover from transplant to flower.
• Plant late (mid-June) or plant a spring squash
trap crop.
Wilted squash- what could be wrong?
Squash vine borer
Squash vine borer
• Very common lethal pest; attacks squashes
and pumpkin.
• Pupae over-winter below soil; moths emerge
in spring and inconspicuous eggs are laid
singly on stems.
• Cream colored larva with brown head; 1 inch
long when mature.
• 1-2 generations/year.
Organic management:
before signs of injury
• Set out 3-4 week old transplants after danger of
frost to get a jump on this pest.
• Cover plants with floating row cover until
flowering to prevent egg-laying.
• Spray lower stems with pyrethrum or spinosad.
• Till soil at season’s end to kill/expose svb cocoons.
• Butternut and cushaw are resistant; yellow
crookneck less susceptible than zucchini.
Organic management:
after signs of injury
• Locate active borers by slitting the vine
vertically where frass is kicked out. Kill borer.
Mound soil over the wound or wrap with duct
tape.
• Seal up infested vines in plastic bag before
larvae pupate (break life cycle.)
Squash beetle
Three life stages of the
squash beetle. Similar in
appearance and feeding
habit to Mexican bean
beetle.
Downy mildew of cucurbits can be a
devastating disease for farmers and
gardeners.
Powdery mildew of cucurbits is very common.
Select resistant cultivars when possible.
Numerous viruses,
transmitted by insect
feeding, may infect
cucurbits. Leaves may
appear distorted, strappy,
and multi-colored.
Non-human animals
also enjoy cucurbits!
Resources
• Grow It! Eat It!
http://www.extension.umd.edu/growit
– We have all types of practical food gardening tips and
information. Check out our popular blog!
• Home and Garden Information Center
http://www.extension.umd.edu/hgic
– Here you will find factsheets, photos, and videos. You
can also subscribe to the free monthly e-newsletter.
– We answer gardening questions 24/7…just click
“Ask Maryland’s Garden Experts”
• Maryland Master Gardener Program
http://www.extension.umd.edu/mg
– Consider becoming a trained MG volunteer!
Many thanks to UME Master Gardeners, especially Grow It Eat
It bloggers, who provided photos and Powerpoint slides:
Erica Smith (head blogger), Nancy Robson, Audra Russell, Kent
Phillips, Donna Koczaja, Nick Tardiff, Lena Rotenberg, Butch
Willard, Sabine Harvey, Bob Nixon
Prepared by Jon Traunfeld, Extension Specialist, and Donna
Koczaja and Nicholas Tardiff, UME Master Gardeners. October,
2013
This program was brought to you by the
Maryland Master Gardener Program
Howard County
University of Maryland Extension