March 21, 2013
Extend growing season with simple steps

While many of us have been comfortable with getting out and doing a little yard cleaning during the recent warm weather, others have developed an itch located somewhere near the first metacarpal bone in their right thumb. Oddly enough, such an itch turns that thumb an odd shade of forest green.

At any rate, it seems that the only reasonable cure for the green thumb is to get out and get something growing — and that is the plan.

The calendar says that spring began yesterday. That is encouraging. The weather has been warm. That is encouraging. We live in Utah and know that the calendar does not dictate the upcoming weather. That is not encouraging to normal folks but those among us with that itchy thumb don’t pay too much attention to things like that. Green thumbers have their ways.

Take for example methods of season extension. If the usual Utah growing season isn’t long enough, or if there is a hankering to be the first one on the block to eat produce from the garden, they will find ways to make it happen.

Of course a greenhouse is the obvious solution, but it is so expensive to cover an entire garden with one.

The key is to warm the soil and the air around plants. Start by finding the best possible microclimate. In every yard, there are spots that are warmer than others. Sunny areas near walls or fences and enclosed in some way for wind protection are generally ready to receive plants sooner than those without those amenities. Dense hedges, simple wooden fences or elaborate brick walls will help with the wind control.

If you have a steep-facing, sunlight-collecting south slope that will be warmer than other areas and isn’t too sloped, it will serve nicely. That slope is also helpful to provide drainage. Getting excess water out of soil allows it to warm up earlier and soggy soils are impossible to till anyway. If you can’t break up the soil, you can’t plant.

Again, the elaborate walls may not be in our budget or garden plan, but home foundations also provide heat. The south side is warmer than the north and the west is warmer than the east. Make use of that radiant heat.

Raised beds, grow boxes or containers are also ready for planting earlier because they drain well when filled with artificial growing mix and the soil is exposed to the sun.

Wall O’ Water and similar devices absorb heat from the sun during the day and release it at night. If temperatures get extremely cold, the water freezes and releases heat in the process. This protects and warms the plants inside and greatly accelerates both planting times and maturity.

Put Wall O’ Waters in place two or three days before you plant the crop so that the soil has time to warm up enough to encourage plant growth. Nurseries often carry these devices.

Hot caps provide some protection from the wind and cold temperatures, but they are more of a shelter than a warmth giving device. They offer minimal soil warming. Nevertheless, planting can be accelerated by a week or two with hot caps, milk jugs or similar devices.

Using protective coverings is not a new idea. Europeans have used glass bell jars since the early 1900s to serve as miniature greenhouses over individual plants. It was a great but expensive idea.

Row covers are another good idea to encourage plant growth earlier in the season. Warm plants by covering those already planted with floating row covers. They are made of a variety of materials including plastics and fabrics. They allow earlier planting and hold in the warmed air limiting the drop in air temperatures at night. Frost protection depends on the outside air not becoming too cold.

Row covers are not particularly expensive and work very well through the winter months to protect fall-planted crops through the bitter cold as well.

Row covers made from plastic resemble small greenhouses. After planting the crop, bend wire pieces to an arch shape and place them about 3 or 4 feet apart down the row. Put the plastic over the hoops. Do not place hoops directly over the plants so that you can create slits for ventilation or irrigation if necessary. Drip irrigation is ideal for covered-row gardening. Hold down the sides with soil or rocks and close up the tunnel to reduce air movement. The sunshine during the day will heat the air and the soil. The soil will release heat to help offset the cooling outside at night.

However, keep in mind that in years with unseasonably warm temperatures, covers do more harm than good. It is best to remove row covers three to four weeks after transplanting.

Put on properly and sealed around the edges, row covers block feeding activity of some insect invaders such as aphids, leaf miners, cabbage loopers and other caterpillars. The cover must be put on before the insects invade however, and any insects that are already in the soil will obviously not be excluded by the row cover. Rotating crops will help evade insects that overwintered in the soil from last year’s crops.

Plastic mulches encourage rapid maturity by warming the soil. Black plastic raises the soil temperature by two or three degrees. The plastic itself gets very warm, but it doesn’t really transmit that heat into the soil very well. Clear plastic focuses the sun’s rays into the soil and warms it better.

Try clear plastic mulch on the soil and put Wall O’ Waters over the plants. The clear plastic can raise soil temperatures by 10 degrees. Crops can be planted earlier and harvested sooner.

Pay attention to the crop varieties you plant. To get an early harvest, use crops that mature quickly. In terms of tomatoes, there are some varieties like ‘Oregon spring’ that have been bred for cooler weather. They may not be as tasty as some of the summer varieties, but a few of those can provide the sandwiches in the early part of the summer while the later varieties are still maturing.

Extending your growing season for an early start may just give you the opportunity to enjoy the fruits of your labor for a longer season. And it will certainly work better than some over-the-counter anti-itch medicine to cure that itchy green thumb.