You Bet Your Garden

The Three Sisters growing technique

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How to correct mis-matched grasses

Chris from Lansdale, Pennsylvania wants to remove a strip of Zoysia grass growing alongside a footpath near his lawn. Mike McGrath recommended keeping it, citing the benefits of this hardy, warm season grass; but if it must be removed, he advised to wait until the fall season when the Zoysia is the most vulnerable and easiest to take up.

What causes a hydrangea to bloom blue?

Melissa from Newark, Delaware is turning her hydrangea into a science experiment. After finding and removing a rusty object buried in the soil around her blue-blooming hydrangea, she wonders if this will effect the soil composition and change the flower color of her plant. Is the rusty object what caused her hydrangea to bloom blue?

Mike McGrath puzzled over the mystery object and then offered:

“You can make the flowers blue by acidifying the soil, and conversely you can make the pink flowers stay pink by spreading a little bit of wood ash or lyme to affect their pH. … This is the only plant I know of that where the flower color can be manipulated like this.

I’ll tell you something that I’ve found that has astounded me as a gardener: If your hydrangeas open up pink in the late spring, you have plenty of time to turn them blue even after they’re open. You can mess with them.

I’ll tell ya the trick that I do is I spread a lot of peat moss at the back of my hydrangeas and some wood ash from my wood stove in front, and I get pink and blue flowers on the same plant … Whatever that element was, (probably iron), there’s probably enough of it in the ground for that plant to absorb for the next four or five years. These elemental things — you know phosphorus, potassium, iron, copper — these plant nutrients tend to persist in the soil and to be taken up very slowly by plants. So I think if you’re going to see any dramatic change, it’s gonna be when the plant has used up the iron or it’s all kind of washed away. But it’d be fun — and like I said, if you want them blue, some peat moss, if you want them pink, some wood ash.”

Photo by Flickr user mum49

Special guest: Umar Mycka

Horticulturalist Umar Mycka talks with Mike McGrath about the perils of poison ivy. Mike shares his poison ivy removal advice and confers with Umar about his methods of identifying and removing this landscape hazard. Umar Mycka professionally removes poison ivy plants from residential and commercial properties in Philadelphia and surrounding regions, including the states of Delaware, New Jersey, and Pennsylvania.

What’s a good flower to feature in a time lapse video?

Joe from Philadelphia, Pennsylvania is looking for a flower to feature in a time lapse video. Mike McGrath recommends marigolds, and then shares indoor lighting advice: “The advantage of fluorescent lights is it’s cool so the tops of the plants can be very close to the lights and that’s when you get your strongest plant growth.”

How to get rid of home-invading insects

Marylin from St. Joseph’s, Missouri is plagued with elder bugs. They’re inside her house and hanging out on the outside of her house, trying to get in. She asks Mike what she can spray to get rid of them. Mike McGrath warns against spraying anything, however, because of the expense and unintended after-effects. His recommendation for removing home-invading insects — like elder bugs, stink bugs, or lady bugs — is to build a an outdoor trap.

“It’s a really easy answer to a problem that just drives people crazy.”

What’s the best way to transplant a tree?

Brad from Nashville, Tennessee is relocating and wants to take a young peach tree from his property with him. Mike McGrath recommends “You need a big container. You ever see these big blue recycling tubs that they put out for people to put their mixed bottles, cans, and other recyclables in? That people they make excellent plant transport containers … You want to take a shovel and you wanna start a good foot, foot and a half away from the trunk and start digging in a circle around it. And then when you make a full circle, start testing, start testing, until finally you can lift up everything — an entire island of soil. You really shouldn’t even see any roots. And then you want to have some good soil already in the container and then you want to have a little bit of help, and very carefully lift this peach tree up out of the earth and drop it down into the container, and then add soil so that the tree is at the same height it was in the ground. Water it if it gets dry, put it in a good spot. With that much soil around it’s roots, and if you don’t disturb it, it won’t know anything is happening.”

Question of the Week: The “Three Sisters” growing technique

John from Edmond, Oklahoma asks: I have set aside an area in my vegetable garden to try The Three Sisters system of growing corn, beans and squash. Do you have any suggestions as to what type of squash and beans to plant? (I’ve been told that I can use just about any type of pole bean (green beans or others) and just about any bush or non-vining cucumbers, squash or pumpkins to cover the ground. And are there recommended varieties for the corn? Get the answer »

The Three Sisters
Photo by Flickr user Rachel Rusinski