You Say Squash, I Say Pumpkin

Is it a pumpkin or winter squash?  Consider your response carefully, because depending on which corner of the world you call home, your choice of words might describe an orange colored fruit of the finest texture prized for both beauty and flavor, perfect fried, boiled, roasted or baked, or for all manner of soups, cakes, puddings.

Or it could be a disdainful reference to a lowly vine grown for cattle fodder.

Adding to the confusion are the prefixes ‘summer’ and ‘winter’, which, when paired with the term squash, do not actually refer to the season in which the plant is grown, but are simply terms which along with depictions of size and shape, are used to describe a particular variety.

While they do vary widely in appearance and certainly uses, summer squash, winter squash and pumpkin  are all closely related cultivars from the genus Cucurbita , including C. moschata , C. pepo , and C. ficifolia , all three of which originate in Central America, and C. maxima , which comes from South America.

C. moschata has been in cultivation for over 5500 years, and includes varieties we would likely describe as both winter squash and pumpkin here in the United States. C. moscata varieties have sweet flavored flesh which is eaten raw, or prepared in pies, cakes, etc.  Included in this group are popular varieties including ‘Waltham’ butternut squash, ‘Pawpaw’ pumpkin, and ‘Tahitian Melon Squash’.  Though bush types do exist, most cultivars from this group grow as a long trailing vine with large leaves.

C. pepo  can take much of the blame for all the confusion in terminology. This group includes popular ‘summer squash’ cultivars that are normally harvested when the fruits are immature like ‘Yellow Crookneck’, and various zucchini and scallop squash types like ‘Costata Romanesco’ and ‘Golden Bush Scallop’.

But also within the C.pepo group are ‘winter squash’ varieties including acorn types like ‘Table Queen’ , as well as turban shaped varieties including ‘Buttercup’,  and ‘Delicata’ – the sweet potato squash.

For those Interested in growing the family’s  jack-o-lantern or a jaw dropping 600 lb. pumpkin, C.maxima  includes the cultivars that we think of as pumpkins here in the US. Varieties from this group, like the monster ‘Atlantic Giant’, grow as vigorous trailer-climber vines with huge round leaves.

While the variety of names may confuse, cultivation of Cucurbita varieties is the same whether you’re growing a giant pumpkin or patty pan squash. Some bush types can be grown in areas with short seasons, but the majority of Cucurbita  cultivars grow as long, trailing vines which require 4-5 months of warm weather. A sunny location, warm fertile soil enriched with compost, and plenty of water are the basic requirements, and planting  seeds or seedlings in hills that are about 2’ in diameter and 12” high improves drainage and helps prevent moisture related problems.  To maximize space in the typical backyard garden, vines can be trained to climb on structures like fences, sheds, pergolas, etc. It’s tough to weed once Cucurbita varieties get established and quickly cover a large area, so it’s helpful to place a layer of mulch around the area before the plant really takes off. Watering established vine canopies in the morning is always preferable to evening watering as the sun will quickly dry the leaves, which are prone to mildew.  

Cucurbita plants have both male and female flowers, and a swollen ovary beneath the petals clearly distinguishes the female flower.  While pollination is normally carried out by insects, it can also be done by hand. Simply cut off a male flower, and transfer some of the pollen into the top of the protruding stigma in the center of the female flower.

Charming, Functional, and Sturdy : Charlotte Country Day School's 8'x12' Greenhouse

Charlotte Country Day School science teacher Taryn Page’s organic gardening program is impressive.  Rows of irrigated raised beds are thoughtfully placed like a feng shui  army formation, with plenty of space for students to navigate between them. The garden sits in an open space, unfettered by overhanging trees, and reels in hours and hours of direct sunlight even in the winter months.  Compost tumblers wait patiently nearby, ready to receive garden waste, while a hutch keeps careful watch over  the garden program’s shovels, hoes and rakes.

Yet, despite the well planned garden and sunny location, the Country Day School’s garden program was still confined to the frost free growing season between spring and fall.  

Charlotte Country Day School's 8'x12' Greenhouse _ exterior from Microfarm Organic Gardens on Vimeo.

A greenhouse was the answer, of course, but Taryn had more options to sort through than Baker Creek’s Heirloom Seed Catalog.

It doesn’t take long to see that the market is loaded with greenhouse options ranging from inexpensive kits framed with plastic or aluminum frames and covered with thin plastic glazing, to heavier gauge aluminum and steel, or wood frames glazed with high performance multi pane polycarbonate or glass.

Charlotte Country Day's 8'x12' Greenhouse _ Interior from Microfarm Organic Gardens on Vimeo.

While their low price points will grab the attention of many gardeners, many prefabricated greenhouse kits are notoriously flimsy, and often rack or even collapse under even modest wind, snow, and ice loads.

And while no one could deny the beauty and elegance of a high end hobby greenhouse placed on a stone knee wall, and loaded with high performance options like triple paned, low E glass, evaporative cooling, gas heat,  an automatic misting system, supplemental lighting, and double doors at each end, these come with a price tag that can rival that of a well  equipped BMW, and  well outside the allowance that Country Day dedicated for this project.

So with budget considerations, and more importantly the safety of dozens of young gardeners in mind, Taryn quickly whittled down the options.

Ultimately she selected a classic, sturdy gable greenhouse design made by Microfarm Organic Gardens, with durable red cedar lumber and shatter-resistant polycarbonate glazing. The Country Day School greenhouse measures 8’x12’ and about 9’ high at the peak.  

The structure was framed with red cedar 2x4 lumber, and studs and rafters are spaced 24” on center to ensure the greenhouse can support  the heaviest wind, snow and ice loads, or even the weight of a person maneuvering along the roof for maintenance.  

The red cedar framework was securely fastened to a level base made with 4”x4” red cedar timbers, and the greenhouse floor was filled with #67 gravel, which provides both good drainage and traction.  

The Charlotte Country Day School greenhouse was glazed with 6mm twin wall polycarbonate material, which has much better insulation value than single pane glass or polycarbonate, and features a special UV protective coating on the exterior.  Polycarbonate is nearly indestructible, and will not shatter like glass, and unlike acrylic or plexiglass, polycarbonate will not turn cloudy or hazy over time. The material even comes with a 10 year performance guarantee from the manufacturer,  Charlotte based Polygal.

In order to help Taryn maintain an optimum grow environment with good air exchange, two manually operated roof vent windows were placed on each side of the greenhouse.

Interested in a similar greenhouse, or perhaps a smaller or larger version for your home or organization? Microfarm will happily build this gable design to any size specifications - as small as 8’x8’, and up to 12’ x’24’.

CLICK HERE to schedule a consultation, or simply email hello@microfarmgardens.com

Amenities That Matter

Sure a media center with a 3D projection TV and high speed internet would be decent amenities to have at your apartment complex , and  an amenities deck with a saltwater pool and custom stone grilling area would pass muster, but what if your residential community had an organic garden? The Vyne Apartments in Charlotte does, and it’s a nice one with raised beds made of red cedar, and finished with pea gravel pathways.

The Vyne’s organic  garden is located right in the center  of the community’s amenity area -  just a back flip from the pool , and close enough to the outdoor grill to toss fresh picked eggplant right into themarinade.

The L shaped bed measures ten feet on the outer sides and the square bed measures  4’x4’.. A two foot wide pathway between the beds allows plenty of room for residents to tend and harvest their favorite heirloom varieties from the garden.

Best of all, property managers at the Vyne have made it easy for garden enthusiasts to meet like minded residents and share their knowledge by organizing a garden club for the Vyne on Central community.

Tomato Leaf Curl

Have you ever seen the leaves of your tomato plants begin to curl or roll up? Several factors including environmental stresses, viral infection and herbicide damage can cause this odd looking condition, which while it may not mean the complete demise of the plant, can severely stunt growth. Examine the plant to determine the cause of the curling or rolling of the leaves…is it just new leaves or all of the leaves? Do the leaves roll upward or downward? Are any other parts of the plant, including fruit, showing signs of curling?

Physiological Leaf Roll
Over fertilization, and excessive heat, drought, careless pruning, and transplant shock are several of the environmental factors that can cause physiological leaf roll in nightshade varieties like tomatoes. Usually symptoms first appear n the lower leaves with an upward curling of leaflets followed by an inward lengthwise rolling of these small leaves toward the middle vein. The affected leaves often become thickened and have a leathery texture, but may retain normal, healthy green color.

Vine tomato (indeterminate) varieties seem to exhibit physiological leaf curl more frequently than bush tomato (determinate) varieties, and while this condition can occur at any time of the growing season, it usually occurs during the transition from spring to summer. While it is an odd looking condition, tomato leaf curl has little to no impact on plant growth and tomato fruit production. Fully hardening off tomato seedlings before planting, taking care to avoid over fertilizing, and maintaining consistent moisture level in the soil, will greatly help prevent tomato plants from developing this physiological problem.

Viral Infections
Several viral infections may also cause leaf curling in tomatoes. Yellow leaf curl virus, for example is transmitted by whiteflies, and new leaves on infected plants become cupped and pale green in color. The entire plant may also show signs of stunted growth, decline in fruit production, yellowed leaf edges, and purple colored veins on the undersides of leaves. Tomato mosaic virus is another disease that causes curling of leaves, as well as other symptoms, including mottle colored leaves, and internal browning of infected fruit.

There is no treatment for virus-infected plants. It is best to remove and destroy infected plants, and because weeds often serve as hosts to the viruses, managing weeds around your garden can help prevent transmission of the virus by insects. It is also important to disinfect tools that may have come into contact with diseased plants in order to help prevent spreading the virus.

Herbicide Damage: Symptoms of tomato plants that have been exposed to herbicide include downward curling of leaves, twisted growth, deformed fruit, and  stems that split or have turned white. Ultimately the plant’s survival will depend on the level of exposure, and while damage cannot be reversed, new growth on the plant may be normal. Be cautious when spraying herbicide as the mist can drift beyond the target area.

Cultivating Sweet Potatoes

HISTORY

While the sweet potato originated in the tropical and subtropical areas of meso and South America, the remarkable journey it made around the world and into the diets of many cultures would impress even the most well-heeled jetsetter. While it is often interchangeable with potatoes in culinary applications, the sweet potato tuber, also called kumara, thrives in warm, humid climates where it is difficult to grow the true potato.

Sweet potatoes are thought to have been domesticated from I. trifada, which is native from Mexico down to Venezuela, and were carried around the world to the South Pacific islands, Egypt, India, New Zealand, Sri Lanka, Japan, and China where it reportedly arrived around the end of the 16^th century.  They reached southern Europe by the early 16^th century – before the arrival of the true potato.

The Taino Indians of the Greater Antilles and Bahamas named the sweet potato batata. The  Spanish gave the same name to the Andean tuber or true potato, thus both tubers ultimately became known as potato, with the sweeter, tropical plant later used termed the ‘sweet potato’ to distinguish the two markedly different varieties of tuber.

Like the potato, there are many varieties of sweet potato developed for various types of food preparation around the world.  Cultivars high in starch are sweeter and commonly used for making crisped chips, candying and roasting, while other varieties are better suited for soups,  stews and mashing.

CULTIVATION

Sweet potato typically grows as a trailing vine, but semi trailing and even compact bush types have been developed to make the most of limited garden space. They thrive in warm weather and when planted well after danger of frost, quickly shade out weeds as the season progresses.  

Outside the tropics, sweet potatoes are commonly grown from rooted shoot cuttings called slips, which are widely available from garden centers and reputable mail order suppliers, and are a fast, reliable method for establishing a backyard sweet potato crop. Reputable mail order suppliers, like Southern Exposure Seed Exchange, for example, often sell certified organic sweet potato slips that are well adapted for a specific region of the country.

Sweet potatoes prefer loose, well drained soil, and a raised planting area that’s 12” deep or more, filled with a light organic soil blend will ensure your sweet potatoes have room to fully develop.

Transplant slips in the garden 3” deep, 10”-18” apart in rows at least 3’ apart. This spacing is crucial to allow room for the sprawling vines to develop. Slips should be transplanted in the evening, and watered in well, with the soil kept moist for the first several days as the plants get established.

Once established, sweet potatoes can perform well with little water or fertilization, but irrigation and even moisture can help prevent splitting and cracks, and side dressing the plants with compost will improve both size and overall yield.

HARVESTING

Sweet potatoes typically require between 90 and 120 days to reach maturity, depending on the variety, and the best way to check the size of your crop is simply to dig one of the plants after the recommended growing time has passed. If they’re still a little small, wait another week or so and try again. It’s best to harvest on a sunny day when the soil is relatively dry. Begin by pulling the vines aside so you can see where to dig, and using a spading fork, start about 12” away from the main stem of the plant, digging 6” straight down, then angle toward the center of the plant and lift the potatoes up out of the ground. Separate the sweet potatoes and dry in the sun for about an hour, handling them gently to avoid bruising.  While they’ll continue growing if left in the ground past the recommended growing period, growth will slow as the weather cools, and for optimum storage quality, they should be harvested before the soil temperature drops below 55 degrees.  

Don’t’ want to wait four months to enjoy your sweet potato patch? The tender shoots and leaves of the sweet potato vine are also commonly harvested,  and used as cooking greens much like spinach ; chopped, steamed, sautéed, etc.  Just be sure to leave enough of the vines and shoots above ground to ensure a vigorous plant that produces a good crop of sweet potatoes below ground later in the season.

CURING & STORAGE

Curing improves the sweetness and storage quality of sweet potatoes, and also allows for the healing of scratches and any other damage. After harvesting, allow the sweet potatoes to dry completely, then  shake off any excess soil.  Never wash sweet potatoes before curing.  Cure them by keeping at 85 degrees and 90% relative humidity for a week to ten days.  A space heater can be helpful in creating these conditions.  For long term storage, choose firm, well shaped potatoes with even coloring and free of bruises.  Small or damaged sweet potatoes can always be washed and used right away. Store cured sweet potatoes in a cool, dry place away from light. Properly cured sweet potatoes will store between 5 and 12 months unrefrigerated.

GROW YOUR OWN SLIPS NEXT YEAR

Start about 8 weeks before planting time, by selecting 1.5” diameter sweet potatoes from high yielding hills. First soak the sweet potatoes in water for two hours, then place them in a pot or flat half filled with soil or compost.  Cover the  sweet potato with another two inches of soil and keep evenly moist in a warm, sunny place indoors. When it’s time to plant, cut the slips about an inch away from the ‘mother potato’ to avoid transferring any diseases. Slips should be about 8-10” long when they’re cut and planted.

Ready to get started on your own sweet potato crop? We recommend the high quality sweet potato slips offered by these reputable suppliers :

Sow True Seed Co.

Southern Exposure Seed Exchange