Tuesday, August 15, 2017

Growing Winter Squash & Pumpkins


It's almost magic! Plant a small seed in a rich spot of earth and vines with gorgeous huge leaves, bright yellow flowers, and cinderella like pumpkins take over the garden.  Winter squash offers so many options to the gardener:  decorative gourds for fall, Jack'o lanterns for Halloween,  seeds to roast or eat raw, pumpkin pies, and long term storage so you can enjoy the benefits of home grown produce through out the fall and winter months.


I love the vast varieties of squash available to gardeners!  From warty to smooth,  from orange, yellow, gray, green, to white colors, and with endless shapes, squash provide variety and interest to your garden.



Squash have been feeding the world since the beginning.  Heirloom varieties have unique and intriguing histories.  I love reading seed catalogs in the winter and planning out what squash will have a spot in my garden that spring.  I always try new varieties as well as old time favorites.

I love the huge vines of winter squash that spread 
through the garden, up the corn, and along fences.


Squash, both winter and summer, are members of the cucurbitaceae family. Summer squash are those varieties who fruit is eaten immature while the rind is soft and there are fewer seeds.  Winter squash are allowed to reach full maturity and have hard rinds and mature seeds.  Pumpkins are also in the squash family.  

 Squash, like all cucurbitaceaes, have tendril bearing vines and are heat loving.  There are 6 different species of squash.  Each species has unique stem, leaf, flower, and seed characteristics.



All squash of the same species will cross pollinate.  Pollination is dependent on insects which randomly move pollen from flower to flower and plant to plant. Bees are important pollinators of squash both native and honey bees. 

 Each plant will produce both male and female flowers.  Male flowers have a straight stem while the female flower have a small immature fruit at the base which is the ovary.


A female flower



Species of Squah



Cuc├║rbita maxima

Long vines, huge hairy leaves, soft round spongy stems.  The seeds are thick white or tan or brown seeds with a cream colored margin.   The seeds also have a thin cellophane coating.

Jarrahdale Pumpkin a blue gray color and ribbed extremely long vines.  The flesh is orange and great for pumpkin pies.

Included in this family are banana , Buttercup, hubbard, Jarrahdale, Kabocha, all giant pumpkins, and turban squash.
Australian Butter Pumpkin

First time planting this variety


Cucurbita mixta

Varieties of this species have spreading vines and large hairy leaves.  The stem is hard, hairy and slightly angular.  The leaves have a rounded leaf tip and few indentations along the margins.  The white or tan seeds have pale margins and cracks in the seed coat on the flat sides of the seed.  They also have a cellophane coating.

Includes most varieties of cushaw or sweet potato squash,  all the wild seroria squash and silver seeded gourds.


Cucubita moschata

C. moschata has spreading vines, hairy leaves with pointed leaf tip and slight indentations, the stem flares out where it attaches to the fruit with beige seeds with dark beige margins. 
Long Island Cheese

Butternuts, all varieties of cheese, belong to this species.  Long Island cheese is a favorite.


The flowers of C. moshcata has large leafy sepals
at the base of the flower.
Butternut

Long Island Cheese named because it resembles a cheese wheel


Cucurbita pepo

All members have prickly leaves and stems.  Stems hase 5 sharply angular sides. Seeds are cream colored and have white margins.  

This species includes all summer squash and the warted decorative gourds found in grocery stores. C. pepo includes all varieties of acorn, cocozelle, crookneck, scalloped or patty pans, and zucchini.
Only the warted pumpkin is of this species

Cucurbita ficifolia

Malabar Gourds are of this species.  They require a very long growing season and are best planted in frost free zones.  The fruits have greenish, cream mottled skin and flat black seeds and the leaves resemble fig leaves.
(Seed to Seed, Suzanne Ashworth) Cucurbita foetidissima

C, foetidissima are known as buffalo gourds with light gray arrowhead shaped leaves that will emit an unpleasant odor when brushed.  The 4" diameter fruits are not eaten; however, the seeds are pressed for oil.  This plant also grows best in frost free zones.
Coyote or Buffalo Gourd growing wild next to my field garden.

These grow wild in my area.  They are also known as coyote gourds or wild pumpkin.  They are perennials sending out vines from a large tuberous  root that can be 16 inches in diameter and extend 3 ft into the ground.  The fruit or gourd is striped and only 3-4 inches in diameter



Buffalo gourds are very drought tolerant with a history of use by native Americans.  The root was used for medicines, the seeds were eaten, and the gourd dried and used in rituals as a rattle.

The leaves when crushed give off a foul odor and which was used as an insect repellant.  The root  foams when water is added and was used as shampoo and for laundry soap.  Do not eat the gourds or leaves as they are toxic. (Medicinal Plants of the South West, University of New Mexico)










Cultivating Summer and Winter Squash

Squash are best direct seeded in the garden.  They do not like their roots disturbed when transplanted.  If you are trying to start seeds early transplant when they have 1-2 sets of true leaves. 

 Squash are a warm season crop germinating best in soil temperatures of 70 degrees.

Before planting the seeds, incorporate organic matterand a handful of dry organic fertilizer into the soil.  Plant 2-3 seeds above the amended area and then thin to one health plant after true leaves appear.  Squash will appreciate an occasional feedings of fish emulsion and kelp.  Also mulch around seedlings after they emerge.  Even moisture is important. 



Pests

I probably get more questions on how to deal with squash pests, mainly the squash bugs, than any other pest.  It is possible to manage this pest organically.  

Success in managing any pest is to know your enemy.  What I mean is to be able to recognize it at all stages.  Squash bugs undergo compete metamorphosis meaning that the bug looks different at each stage.  

Here is the squash bug in all stages:



Bronze colored eggs laid usually laid on the underside of leaves in-between the veins.
The nymph which resembles a small grayish, black this is the ideal stage to kill the squash bugs.  Adults are harder to kill.
Life cycle of the squash bug:

  • Unmated adults overwinter in debris and in structures.
  • In April or May the adults emerge and fly to cucurbit crops to mate and lay eggs.  In southern Utah 2 generations are possible.
  • The female lays up to 250 eggs
  • The new generation will appear in June or Julyand feed on the host plant to build up reserves for winter.


Cultural Controls
Because the adults can develop resistance to insecticides, even OMRI insecticides, good cultural practices are necessary to manage this pest

Monitor for squash bugs

  • examine the leaves looking for eggs smash rub off any you find.
  • Watch for signs of feeding damage which include yellowing and browning leaves.
  • Heavy feeding results in leaves turning black and crisp or wilting of leaves.
  • Squash bugs feed on vines, leaves, and the fruit with piercing sucking mouth parts.  They feed on the sap and can disrupt the flow of water in the xylem.
Check the base of plant for nymphs


Cultural Practices to control squash bugs

  • Examine plants weekly hand pick adults and remove eggs
  • Maintain healthy plants through proper fertilizing,  organic matter, and proper irrigation.
  • Remove all plant debris including vines and fruit of all cucurbits that includes cucumbers and melons
  • Rotate the your crops.  Do not plant squash in the same spot every year.  You can also plant squash every other year if populations of squash bugs are overwhelming.
  • Plant as early as possible so plants are healthy and established before squash bugs emerge
  • Late plantings also seem to work



Organic Pesticides
These are most effective on nymphs with pyrethrin being effective on adults.

Pyrethrins:  effective on adults be sure to use organic not synthetic.  Pyrethrins kill on contact and affect the nervous system.  Spray in early morning or evening to protect beneficial insects.

Neem:  Growth inhibitor.  Must be ingested and prevents molting and reproduction so it does not kill on contact.  It is systemic and taken up in the plant tissues.

Spinosad:  This is a bacteria or microbial insecticide effective on nymphs

Kaolin Clay or Surround:  A protectant which discourages feeding
If you have a large area consider using a tank that hooks to a
4-wheeler

My Approach:

I monitor a couple times a week.  I remove eggs and hand pick any adults I see.  Once I see nymphs I spray.

I add the following in one sprayer:

  • Pyrethrin
  • Neem
  • Kaolin Clay


I spray and then recheck the next day and spray any I missed.

Look at the base of the plant where they congregate.  Also if you monitor while irrigating the insects will come out of hiding and move to the top of the plant.

After my vines are very mature I let my ducks in the field they love squash bugs.

(Utah Pest Fact Sheet USU Extension)
Healthy leaves no sign of squash bugs





Harvesting Winter Squash


Patience is necessary when harvesting pumpkins and squash.  The hard rind is what makes long term storage possible and that takes time.  Plan your plantings to be harvested before a frost.  If a frost is expected you can cover the fruit with a tarp or blanket.  

Pumpkins and squash are ready to harvest when
the rind does NOT indent when pressed with your thumbnail. Some of the vines may have begun to die back and the color will be solid.

Cut don't pull or rip the squash from the vine.  Leave a 2-3 inch piece of stem.  If you break the stem use those up first because they will not store long.

Cure the squash or pumpkin for a week or two in sunlight.  The exception is acorn squash.  Put it in storage when harvested.

Store in a cool, dry well ventilated area that gets no colder than 50 degrees.

Delicata, acorn, and spaghetti squash can store up to 2 months

Pie pumpkins, hubbard, and buttercups store 4-6 months

Butternut and cumshaws store up to 8 months

I recommend you read about the storage length of the varieties you plant.



Color will deepen and rind will harden as this ripens
Damaged or dent pumpkins and squash can be used for fall decorating.

Friday, August 4, 2017

Cucumbers: So Many Flowers; So Few Fruits!





Understanding flowers and  bees may answer your questions about why so many flowers and so little fruit  are setting on your cucumber, melon, or squash plants. Squash, melons, and cucumber belong to the family of cucurbits and they have a unique flowering method. Melons, cucumbers and squash are monoecious meaning they produce both male and female flowers on the same plant.




Male flowers are produced before female flower.  So that could be one reason you have no fruit. Early in the season female flowers may not have developed yet. 


 For fruit to set, pollen from male flowers must be transferred to the female flower.  This is done by bees whether native or honeybees.  If no bees are present there will be no fruit.  If few bees are present and pollination is poor, the result will be few and misshapen fruits.  Drought stress can also cause misshapen fruit if bees are plentiful.  


Male & Female Flowers

So how do you tell a male flower from a female flower?  This is easiest to do in squash.  All female flowers have a miniture fruit at the base of the flower.  

 The stigma of the female flower of a squash.



 The flowers of this particular pumpkin are very large so it is easy to see the bulge or ovary of the female flower.  

Male flowers have straight stems with no bulge at the base.




A male squash flower with the stamin that produce pollen in the center. Bees are busy at work in this flower.  The pollen will stick to the bees and transfer the pollen to a female flower.
 

Notice that the stem at the base of a male flower is straight with no bugle or fruit shaped ovary.  Male flowers are viable for only one day.
 

After a day the flower shrivels up and dies.  Each day new male flowers open. 


In cucumbers and melons, male flowers have very short stems and grow in clusters of  3-5 flowers. There will be an abundance of male flowers and very few female.


 Another male flower

Notice at the base of each male flower is a straight stem.

Female flowers grow individually on longer stems with an ovary that resembles a miniature cucumber at the base. They are hard to find because the male flowers out number them.









 I had to hunt to find this female cucumber flower.




 A pollinated female flower of an Armenian cucumber.


An immature pickling cucumber.  You can see the shriveled flower at the end.


Hand Pollinating

If bees are not present or too few in number, then hand pollinating is an option.  Pollen is yellow and produced in the center of the male flower.  Use an small paintbrush to transfer the pollen to the stigma of the female flower or tear off the petals of the male flower and roll it in the center of the femal flower. 


 Gather the pollen from several different male flowers. Use only freshly opened flowers. This occurs in the morning.


Hand pollinating cucumbers can be tedious.  It is often difficult to find female flowers.  
 
If you provide a water source, lots of nectar producing flowers that attract pollinators, and have healthy cucumber plants you are less likely to have pollination issues.



Reasons for Poor Pollination

The fact that the individual flowers of cucrubits remain open only for a single day means they must be pollinated that day or the flowers drop from the vine.  If the weather is not favorable for bees then  flowers that open that day will not be pollinated and set fruit. 

Bees  are hard workers but do take off windy, rainy, or sometimes overcast, cool days.  They prefer bright sunny days to do their work.

Many seeds are produced inside a cucumber, squash, and melon.  Amazingly each pollen grain is responsible the development of a single seed.  Numerous bees visit each flower to accomplish that task. Providing an environment attractive to both honeybees and native bees is helpful.



 Avoid chemical pesticides and if using an organic spray do so in the evening after pollinators are finished with their work

Healthy cucurbit plants are essential to set fruit.  Powdery mildew, leaf spot etc can be prevented by trellising vines off the ground to allow for good air circulation.

Mulching around cucumbers and regular adequate watering are also essential.



 
Armenian and Summer Dance are my favorite varieties for slicing cucumbers.  Most pickling cucumber varieties seem to do well.