Northern Nevada outdoor gardening: Freezing temperatures and the irrigation dilemma

It’s the annual conundrum. Is it too soon to turn off the irrigation system? With recent nights down to the teens here in Washoe Valley, we turned off the irrigation system and drained it prior to the forthcoming hard freezes. Then we turned off the outside water and drained the hose bibs too. Yet with temperatures last week back in the 60s with low to mid-30s at night, I’m sure I will have to irrigate again soon.

Trees can’t go the rest of fall or through the winter without water, especially when the temperatures are mild and the days are sunny. While only evergreen trees lose water through their needles (their leaves) all winter, both they and the leafless deciduous trees need their roots hydrated to survive the winter. We are probably in for quite a dry winter this year unless the expected La Niña is kind to us, which is unlikely.

To water again I will either have to close all the in-ground drains for the sprinklers, turn the system back on and then re-winterize it, or drag hoses to every tree. It’s a pain, but every year I do it, because I love my trees!

Prepare your plants, particularly trees, for the probable dry season by watering deeply on a moderate day. Then, watch the weather reports. When hard freezes are expected (below 28 degrees), turn off the irrigation system and winterize it. If, or I should say when, there are prolonged dry periods of three weeks to a month, turn your irrigation system back on and water deeply again.

The lawn, unless it’s newly planted this year, will be fine. However, if you don’t want to re-winterize your irrigation system each time you water, drag hoses and sprinklers around to each tree, rose bush and any newly planted shrubs as I do. Be sure to drain the hoses when irrigation is completed, disconnect the sprinklers, turn off your outside water and drain the hose bibs. That’s winter plant maintenance in an arid environment.

Here is a correction to my garlic article below. My friend Arnold Carbone of Glorious Garlic Farm pointed out “Your method for when to harvest is more for onions. Harvesting garlic is an art that depends a lot on observation and weather conditions. The plants should always have some green leaves on them before you harvest.” Arnold says “When the garlic leaves begin to turn yellow in the summer, stop irrigating for two weeks and then pull up the plant. Immediately place plants in a shady place to cure.”

Plant Garlic Now

Garlic is relatively easy to grow. September through the end of October is garlic planting time. Garlic requires a loose sandy loam soil with good drainage and a pH of 6 to 7. The looser the soil, the bigger the bulb. My friend Arnold Carbone of Glorious Garlic Farm recommends this soil mix particularly when growing in raised beds or containers: 1/3 top or potting soil; 1/3 bulky organic material, such as aged compost or manure; and 1/3 sand. Garlic needs a minimum of six hours of sun per day.

Plant only high-quality, disease-free seed garlic, because garlic is prone to diseases that can contaminate soil for years for it and other alliums such as onions, shallots, leeks and chives. Avoid planting garlic in the same place where you have grown other alliums for three years to avoid cross contamination. Garlic ‘seeds’ are the individual cloves of the bulb rather than traditional seeds.

Dig a furrow, amend with compost and a sprinkle of bone meal (phosphorus). Place the cloves pointy end up four to five inches deep and five inches apart from each other. Rows should be 10 inches apart. Fifteen cloves per square yard is a good rule of thumb according to Arnold. There is no need to strip the paper skin. Cover with more soil blended with compost, and put three inches to four inches of mulch on top. Put netting on top of the mulch to hold it in place in the wind. The mulch will reduce soil heaving due to frost.

Water thoroughly at planting and again through the fall and winter only when the soil is dry. Do not overwater because garlic rots easily. Raised beds and containers may dry out more readily than in-ground plantings. Fall planting allows roots to develop slowly over winter for strong hardy spring growth. Garlic emerges in March to April.

Feed garlic plants twice in the spring with liquid kelp or fish emulsion. “Garlic doesn’t like company” (Carbone), so keep weeds and other plants away. Cut any flower stalks that appear and use them in cooking. Otherwise, the garlic will go to seed and the crop of bulbs will be tiny. Stop watering when the tops fall over (mature). Excess water as the crop matures causes bulb splitting, delays curing and may cause storage problems

Start harvesting when the fallen garlic tops begin to yellow. Use a spade or garden fork to lift the bulbs from the earth. Store excess garlic by drying.

— JoAnne Skelly is an Associate Professor & Extension Educator Emerita at the University of Nevada Cooperative Extension. She can be reached at skellyj@unr.edu.