FOR RELEASE THE WEEK OF AUG. 2, 1999:
We’re finding blossom-end rot on our tomatoes again this year. None of our neighbors have this problem. What causes it and how can we prevent it?
Blossom-end rot–black, sunken, dry spots that can cover half of a tomato’s surface–results from calcium deficiency and moisture stress. Correcting these conditions is how you prevent the malady, says Michael Colt, University of Idaho extension horticulturist.
In northern Idaho gardens, the key is adjusting the soil pH to 6.0-6.5 by adding lime. That’s best done in the fall, but you can also apply a calcium fertilizer such as calcium nitrate in the spring before planting.
In southern Idaho, most soils already have plenty of lime, but calcium uptake in the tomato fruits may be hampered by excessive nitrogen and potassium. Use moderate amounts of blended fertilizers.
Calcium uptake requires adequate soil moisture and well-functioning plant roots. Protect tomato roots from damage by restricting cultivation to the top 2 inches. Irrigate to a depth of 2 feet, never allowing the soil in your tomatoes’ root zones to dry out, and conserve moisture with mulches.
Gardeners usually become aware of blossom-end rot when plants have grown rapidly and luxuriantly during the early part of the season and are then subjected to dry conditions when the fruit is in its early development. If you see early symptoms of water-soaked areas at the end of the fruit opposite the stems, remove the affected fruit and provide adequate irrigation.
We have a small acreage and recently purchased several ewe lambs. At what age can we breed them?
A ewe lamb will first become fertile when she is 6-8 months old and may be bred at 8-10 months if she is well developed, says Kathy Roy, University of Idaho extension educator. If she conceives, she’ll lamb in about five months–or when she’s 13-15 months old.
Most sheep are seasonal breeders, with ewes showing signs of fertility during the fall. Some breeds such as Dorset, Polypay and Finnsheep do have longer breeding seasons and can be used in accelerated lambing programs.
Regardless of the breed, sheep fertility responds to shorter days, Roy says. As the amount of darkness increases, the pineal gland secretes melatonin into their blood streams. This hormone stimulates ovulation and estrus, or heat.
August, September and October are the most common months when ewes in Idaho become fertile again and breeding begins. The vast majority of lambs are born from January to March.
We live adjacent to rangelands and have grasshoppers in our garden every year. Besides chemicals, what control options do we have?
"There’s no easy solution to grasshoppers," says Ed Bechinski, University of Idaho extension integrated pest management specialist. "If you’re against wide open expanses of ground, you will be invaded by grasshoppers. Just expect them."
The microbial insecticide Nosema locustae works specifically on grasshoppers, but it needs several years to knock down populations. Over a single season, gardeners using the biocontrol agent won’t notice a decline in grasshopper numbers.
That leaves the alternatives of row covers or netting for the plants you really want to protect–or a broad-spectrum insecticide like Sevin. Unfortunately, Sevin also will kill beneficials. Bechinski recommends that you avoid using it on blooming plants because it is "too hard on bees and other pollinators."
Bechinski suspects that grasshoppers may get more than their fair share of the blame for the accumulated leaf holes and tatters gardeners see as the season progresses. "A lot of the times, I think we exaggerate their impact," he says.
I have heard that green manure can improve my garden soil. What is green manure and how do I apply it to my garden?
Green manure is any green and growing plant that is plowed or tilled into the soil, says University of Idaho extension educator Brian Finnigan. Green manure adds organic matter to the soil, increases microorganism activity and improves soil tilth and nutrient availability. It also has been shown to reduce some soil-borne root diseases in vegetable crops.
A good way to apply green manure to your soil is to plant a crop like barley, rye, vetch, Austrian peas or rapeseed in August or September, Finnigan says. Allow at least six weeks of growth before freeze-up, providing water and fertilizer as needed. Then till the crop in, leaving some plant residue on the soil surface to prevent erosion and to trap moisture-yielding snow.
If your season allows, you can also produce green manure in the spring. Plant as early as possible and incorporate the green manure thoroughly before you sow or set out your garden vegetables.