Equal fertilizer numbers are not necessarily a good thing

A lot of people rely on fertilizer with 10-10-10 on the label. Mike McGrath, host of You Bet Your Garden, will reveal why it’s one of the worst things you can give to your plants and why equal numbers are actually unbalanced. Plus Mike speaks with Mary Gardiner about her new book Good Garden Bugs and your fabulous phone calls.

Question of the Week:

“I’ve been having issues with a pin oak, and one of the suggested fixes was an application of 10-10-10. I had a bit left over afterward and sprinkled some around two ten-inch high cherry tomato plants as an experiment. All my other plants kept growing, but the two I gave the 10-10-10 to first looked stunned, then wilted and are now about to expire. How could a “fertilizer” be the end of these plants?”

— George in Norristown, PA

Find out more about soil tests, sick trees and fertilizers »

Highlights from show for June 28, 2014:

High-Altitude Blueberries

Ken from Costa Rica wants to grow blueberries on the slopes of a volcano back in the place he calls home. Now, Ken has been living down in Costa Rica for thirty years now and he has been searching for new plants for small independent farmers down there in order to help them hold onto their plots of land. Now, among the issues he is taking into consideration are the day length, and the short period of frost that he’d be getting up on the mountain. Having been a farmer in Northern Vermont, he’s seen blueberries grow in the alpine climate up there, but he says the soil may be more acidic up there. Mike agrees that one of the nice things about growing up in the mountains is that even though Costa Rica is largely tropical rainforest, there is a much more pronounced cold season, and that allows for the growth of cold-loving plants like blueberries and even blackberries. Ken tells him that the temperature is largely constant year-round. At the highest altitudes, the temperature is never higher than 80 and never lower than 30, usually hovering around the 50 degree range. And another nice thing about where Ken is situated is that “you can go down the mountain and grow pineapple, or go right up and grow brussels sprouts.” Mike says that he would likely be able to get the right amount of “chilling hours”–meaning hours where the temperature dips below 42 degrees, not necessarily below freezing–for traditional varieties of blueberries growing higher up on the mountain, but he also recommends that Ken try out some of the varieties bred for southern climes, as these varieties, in his climate, may even grow fruit year round. “You may get the kind of extended season that people only dream of!”

Rain Barrel Water

Amy from Wisconsin recently installed a rain barrel and, after hearing all kinds of different conflicting information on the internet, she wants to know if it’s safe to put the water from this barrel on her vegetable garden. Mike replies, “Yeah, otherwise, why would you have it?” Now, Wisconsin hasn’t yet had any dry spells this season, so Amy has been collecting quite a bit of water in this barrel. Mike mentions that rain barrels are more useful in drier climates, or at least ones that go through dry spells. Even though she has this great source of water, it’s dangerous to drown the plants. Another thing that Mike mentions is that rain barrels are really useful for watering containers, as containers, being aboveground, are likely to dry out very quickly. If the rain barrel is high enough to fill a watering can from, then it would be easy for her to use the rain barrel water to water her containers, and that rain water doesn’t contain all of the adulterants such as chlorine and fluorine added to water to make it potable. Mike asks what sort of bad things people have been saying about rain barrels, and Amy mentions that there might be things like bird poop on the roof running off into her rain barrel, but she figured that the birds are pooping all over her vegetable garden anyway. Mike responds that bird poop is a great fertilizer, so that while the water isn’t safe to drink, it’s great to put on the garden. However, shingle debris from the roof is a much greater concern, which is why the spout in these rain barrels is usually a bit higher than the bottom. The solids sink to the bottom allowing one to decant it, leaving the potentially harmful solids behind. The water is very good, however after a period of time, if it just sits there unused, it can turn into what’s called black water just by sitting in the sun. “It wouldn’t be a bad idea to drain it and allow it to refill like once a month.”

Featured Interview: Dr. Mary Gardiner

Mike speaks with Dr. Mary Gardiner, author of Good Garden Bugs: Everything You Need to Know about Beneficial Predatory Insects. Mary gives us a sneak peak into the world of beneficial insects and why they are so important to the health of a garden. Just because something is moving doesn’t mean its bad! In fact many insects you might label as a pest are actually eating the real pests; the ones that are damaging your garden. Good Garden Bugs is a great reference guide for the strange, often wacky and wonderful world of beneficial insects.”

Japanese Beetles

Patty from Philadelphia was recently given the task of shaking Japanese beetles off of her parents’ cherry tree, but she noticed that every time she did this, they would always just come right back. She noted that they have the traps hanging up there, and Mike tells her that she should do away with those traps, as that’s probably the reason why they keep coming back. “Japanese beetle traps attract four times the number of beetles to a given area than would occur normally, and only kill half of them,” thus effectively doubling the Japanese beetle population on the property. There are feelings that you can get the most out of them if you put them around the outskirts of your property away from anything growing that they like to eat, but Mike recommends that she not even bother with them. Patty asks if he has any recommendations to control these seasonal garden pests, and Mike says that he does, in fact. He’s recently fallen in love with a brand new offering from Gardens Alive, who are, quite coincidentally, the sponsor of the question of the week. Gardens Alive has been at the forefront of funding new discoveries in organic pest management, having paid the EPA registration for corn gluten meal, many years ago. They’ve recently released a new form of BT, a naturally-occuring soil organism that has multiple subspecies which can kill all kinds of pests, each one specialized to a different pest. This subspecies is known as BTG, and ONLY AFFECTS BEETLES who eat the leaves. There are two varieties, one you spray on the leaves to kill the beetles, and another you spray on the ground below the plant to kill the grubs before they hatch. “You get the eaters, and you get the next generation, and you don’t harm anything else: these BTs are highly specific!”

Trees and Phone Lines

Lynn hails from Easton, PA in Bucks County, home of one of the best farmer’s markets in Bucks County, and she has an issue with her silver maple. Now, this tree has been growing into the phone lines nearby, and she doesn’t have the kind of dough to maintain it. She’s been unemployed for about a year now, and has been looking for someone to help her take care of this tree, but the quotes she’s received from pruning services have been astronomical. She’s also considered taking the tree down, but not only is the monetary cost too high for that, so too is the emotional cost for her to remove this beautiful old tree. Lynn also notes that this shouldn’t be necessary, as the tree is actually quite healthy, aside from a bit of ivy growing on the trunk. It’s just growing up into the phone lines, so if it isn’t trimmed soon, it’s going to be a problem. Mike comments that if that’s the case, she doesn’t have to bear the cost of it, and that taking care of the ivy won’t be too cost-intensive for her, since it’s not poison ivy. She’s tried to trim along the bottom, and while that’s killed the ivy up on the tree, it’s done nothing to the ivy down in the ground. Mike says that ivy can block sunlight and keep moisture on the bark, causing the bark to rot, killing the tree. And she doesn’t even need to worry about accidentally cutting into the bark as long as she doesn’t cut a ring around the trunk, preventing water and nutrients from getting up to the top. But she doesn’t have to pay for the tree maintenance, as that falls entirely on the phone company or cable company. “They’ve got the trucks to do this, and if the lines are right there on the tree. It’s not so much that it’s their responsibility, they don’t want you or private workers up there. You could knock out the power to all of Easton, you could knock out everybody’s cable TV during the world series! All that I’d suggest to you to keep this tree healthy is to just keep gettin’ away at that ivy.”