This has been a tough year for gardeners throughout Montana, as well as in other northern parts of the country where it's been a bit cooler than normal. As a result, vegetables aren't doing as well as they should this time of the summer, and it raises questions from a lot of gardeners.
I wrote a story that ran a couple of weeks ago for the 'At Home' section of the Great Falls Tribune that addressed many of these issues. (Writing for this section is one of my favorite projects. I'm able to meet a lot of our tremendous Great Falls' gardeners and answer questions for all of us who scratch our heads at what's happening to our beloved plants!)
My big problem this year is herbicide damage. I used the composted horse manure from the stable at the corner that uses weed seed free hay because I thought I was being smart about keeping the weeds out of the garden. Little did I know, I was killing my plants due to the residual herbicide from keeping the pasture weed free! The "fiddle head" appearance on the tomatoes is one tell-tale sign of herbicide damange. I just hope it's going to remedy itself for next year. 
After months of diligently caring for plants - protecting them from spring frosts, hungry herbivores and plagues of grasshoppers - gardeners are beyond frustration when their plants fail to thrive.
Most gardening seasons offer some challenges, but occasionally a particular year turns into the “perfect storm” of garden problems. Many conditions affect plants regardless of the weather, although unseasonably cool temperatures don’t help.
This is particularly frustrating for newer gardeners. “This is the first garden we’ve had in 20 years,” said Dixie Hromcik. “I was hoping to get more tomatoes than I think we’re going to get.”
Hromcik grows the beefsteak tomatoes her father raised in the Saco area, not exactly a banana belt when it comes to gardening, but this summer’s cool nights are hampering growth. “Tomatoes don’t like it below 45 to 50 degrees,” she said.
“They have blossoms, but I don’t have enough tomatoes,” Hromcik noted.
Marcia Bundi of Bundi Gardens in Great Falls is used to fielding questions on plant issues.
“Some people find their blossoms are falling off,” she said. “That’s linked to the cold nights and cold weather. Get some floating row cover, and throw it over the plants. It keeps in the latent heat.”
“If it gets above 90 degrees take it off,” she recommended. Bundi also said if gardeners use sheets or plastic to remove them every day, regardless of the temperature, since they don’t allow the same amount of air and light flow as the lightweight floating row covers.
Bundi said they covered their own tomatoes loaded with green fruit that refused to ripen. On Tuesday they tossed over the row cover, and by Saturday they were picking red tomatoes.
Regardless of this summer’s cool weather, there are other issues that influence growth and production.
“The biggest one is blossom end rot,” said Bundi. “It’s a physiological problem, not an insect or disease.”
With blossom end rot, the fruit will rot at the lower half of the plant. This happens with tomatoes, as well as peppers and eggplant. Bundi said the cause is either uneven watering or a lack of calcium from either not having enough calcium in the soil or the plant’s inability to utilize it properly.
“The easiest thing to do is to watch the water,” she said. Make sure it stays evenly most without extremes either way.
For a calcium defiency she said, “Save your eggshells.” She stockpiles her family’s eggshells in a bucket throughout the year.
“They dry out really fast, and they don’t stink,” Bundi noted. “Crunch them up and mix them with your soil.”
Another common problem is the tomatoes cracking and splitting. “This is uneven soil moisture,” said Bundi. When given lots of water, the tomatoes grow too much and split.
Some varieties, such as ‘Early Girl,’ are more prone to this condition, so besides watching the amount of water, if this is a frequent problem, choose hybrids that are less likely to split.
Cat facing, which is when the tomato has a scar-like line down the middle, is due to incomplete pollination from our cold nights according to Bundi. You can cut around the scar, and still use part of the tomato.
Even with our cool and cloudier summer, sunscald is still an problem. “If there isn’t enough foliage to cover the fruit, it sunburns,” said Bundi. “This is why we don’t advocate taking the leaves off of our tomatoes. The foliage is the energy factory for the plant.”
However, if you have indeterminate tomato varieties, the ones that keep growing as long as the weather permits, Bundi suggests pinching back the tops so the plant puts the energy into ripening the fruit instead of growth.
If leaves begin to turn brown or exhibit characteristics such as concentric circle patterns (shaped like a target) or what looks like water soaking spots appearing on leaves, you most likely have blight. This fungal disease can occur at any time of the gardening season, and is carried in the soil.
“If you mulch you don’t have this problem usually,” said Bundi. “If it does blight, pull it out and throw it in the garbage, not the compost pile.” Most compost piles do not reach temperatures high enough for long enough periods of time to kill the spores. If you don’t completely remove the offending plant, you can spread the disease.
Blight can also occur on potatoes so watch for similar leaf abnormalities.
Even though the weather is cooling more rapidly than most gardeners would like, Bundi recommends leaving the tomatoes and peppers on the plant as long as possible. “If you pick a green tomato and sit in on the windowsill, it will turn red,” she said. But since it’s no longer on the plant, it’s not truly ripe, and the taste is drastically different.
“Be especially careful with heirlooms,” she cautioned. “They don’t like our end of season weather.”
Unless the temperatures warm up considerably for the last remaining weeks, which is not likely, it’s important to provide as much protection as possible to encourage ripening. “Just pretend it’s fall and cover them. You can do it with all of the heat lovers.”
Another issue popping up throughout the state is herbicide damage in home gardens.
Melissa Graves, plant identification specialist at the Montana State University’s Schutter Diagnostic Lab, said “we’re thinking there are more people putting in home gardens, and when they do that, they want to be more environmentally conscience.” This means using manure and compost, but sometimes with unforeseen results.
When a home gardener uses grass clippings from another source than his own yard he might not know whether it’s been sprayed for broad leaf weeds in the lawn several weeks before. The 2,4D in common lawn herbicides remains in the clippings, and can cause serious damage to many vegetables.
The effect is the same if a lawn service doesn’t watch wind direction when spraying. If an herbicide drifts onto the vegetable patch the peppers may suffer the same fate as the dandelions.
“It’s not anyone’s fault,” said Graves. “It’s a lack of communication between all parties involved.”
Herbicide damage looks different than insect damage or disease. “You get stunted growth, bizarre curling of leaves. It doesn’t look like the same plant,” said Graves. Oftentimes, tomato leaves are described to have a “fiddle-head” appearance.
The most sensitive plants are tomatoes, potatoes, peas, beans lettuce and spinach, as well as roses and dahlias.
Another contamination source is using manure unless you’re certain the animals didn’t graze in a pasture sprayed with herbicides to control weeds, which is common throughout Montana, particularly in operations that produce certified weed seed free hay for livestock.
Graves also recommended applying manure and compost at the appropriate rate: one-half inch of compost worked into six inches of soil. More than that could provide an excess of nitrogen, and she said using that amount minimizes the potential damage in case of herbicide residue.
“Tilling also helps break it down,” she said.
If garden plants are affected, Graves said there are a couple of options to remedy the situation.
“Don’t use the garden area the following year,” she said. Some herbicides break down rather quickly, within 30 days, but others can remain in the soil for 12 to 18 months. Some are even longer.
Other options are to remove the contaminated soil, or grow grass crops, such as corn or wheat, since these varieties aren’t affected by the most often used herbicides.
Since the herbicide can be stored in the vegetable, albeit in incredibly minute amounts, it obviously can’t be considered organic for sale.
Finally, she said they’ve had limited success adding activated charcoal to the soil. Graves recommended 5 pounds per 100 square feet tilled into the soil.
The best way to prevent herbicide damage is to be extra aware of your amendment choices, and to be certain no herbicides were used. “It’s a major lack of information,” said Graves. “You need to know where it’s produced.”
