Cucurbits in your Vegetable Garden

1. Cucurbits in your Vegetable Garden Jon Traunfeld, D. Koczaja, and N. Tardiff

4. 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.”

5. 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.

6. 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.

7. 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.

8. Sex and the cucurbit

9. Cucurbit flower structure

10. Wanted: native bees; must be able to lift and transport pollen from male to female flowers (we also welcome European honeybees)

12. 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).

13. Deal with weeds or they will ruin your garden!

14. 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.

15. 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

16. Synthetic mulches • Black plastic mulch warms the soil for earlier, higher yields of warm-season crops, like melons. • Landscape fabric warms soil the soil and is permeable air to water. Can be re-used.

17. Drip irrigation: saves time and water

18. 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

19. 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 heavy clay soils • Work in 2-3” compost prior to planting • If needed, fertilize at blossom, and 3 weeks later GE 108: Cucumbers

20. 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

21. Melons(Cucumis melo) • 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 2010 GE 115: Muskmelon

22. 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

23. ‘Minnesota Midget’ above ‘Tigger’ below

24. 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 2011: this is only 1 plant! GE 130: Watermelon

25. 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 white to pale yellow

26. Watermelon, Japanese style

27. Watermelon’s distinctive lobed leaves Audra Russell, UME Master Gardener, with impressive harvest ‘Yellow Moon & Stars’, an heirloom cultivar

28. 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

29. 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

30. 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!!!

31. Scallop or patty pan squash Yellow straightneck squash Zucchini fritters or bread anyone?

32. Prevent fruit rot disease by removing blossoms from enlarging fruit. Natural color pattern in zucchini leaves.

33. Winter squash/pumpkin(Curcubita spp.) • Some are the same species as summer squash (Cucurbitapepo), 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: • Vining plants take a lot of space • Mature in 80-105 days from seed Immature spaghetti squash GE 131: Winter Squash

34. 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

35. 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!

36. Spaghetti squash above and butternut squash below.

37. Cheese pumpkin So many kinds of winter squash and pumpkin!

38. ‘Tromboncino’ squash

39. ‘Cucuzzi’ gourd (white flower) The vines grew up into this gardener’s trees. Fruit elongate rapidly and are tender at 4 ft. in length.

40. Cherry tomato Mouse melon Mouse melon

41. 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

42. Biological control • Give mother nature a chance! • Predators eat pests • Parasitoids lay their eggs on or in pests

43. Natural predators Orb-weaver spider Assasin bug Lady beetle larva

44. Tiny, non-stinging wasp parasitoid inserting eggs into aphids. The wasp larvae hatch out and eat the aphids from the inside.

45. 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!

46. Floating row cover supported by #9 wire above and pvc pipe below. Enviromesh protects crops from insects and wildlife.

47. 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

48. 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

49. Spotted cucumber beetle Striped cucumber beetle

50. All plant parts are affected