Q: Can I plant coriander in a container on a sunny patio? Also, I have a potted mint plant growing for the last two or three years that was doing well, but not now. What more can I do?
Florence Salama
A: Coriander would do well in a container on your sunny patio. Soil should be rich and well-drained. Its easy to sow coriander too thickly. If its spaced five or six inches apart, the plants are stronger and leafier. But some people sow thickly anyway then thin and eat the plants as they develop.
Coriander can survive through a mild winter. If you want to try this, you could move it in late fall into a sheltered spot.
Mint likes part shade, moisture and rich soil. But no matter how well you treat it, potted mint left unrenovated starts dying out after a while.
You can keep mint fresh and growing in a container by cutting one or two pie-wedges out of the existing growth, removing the roots and that portion of the soil. Old mint roots are thick and tough so you need a very sharp knife or a serrated freezer knife.
Discard the old roots youve lifted out of your wedges. Dont compost the roots because parts of them may begin growing. City green waste bins are the best place for aged mint.
You can compost the old soil if you can separate it from the roots. But the wedge holes should be filled with compost. The mint will quickly occupy the space. Mint needs a constant supply of new, fresh soil to grow well. Thats why its invasive in the open garden.
If your mint pot is on soil, mint roots may reach out through drainage holes.
Q: I have a wonderful tomato plant with a dozen or more tomatoes getting ripe. But a fat, green worm fell off a leaf. I saw another one today and they are hard to kill. I tried an insecticide and finally used hair spray. What else can I do and how can I tell if there are any more?
Eileen
A: This sounds like the tomato hornworm. Its active at night. You could go out with a flashlight and hunt for more. If you could bring yourself to handpick them and stomp on them, this would be a quick, organic, easy and safe solution. Safe for you and safe for the fruit.
Some gardeners throw slugs on the road in hopes a car will squish them. This would also work for hornworms. Hornworms could also be euthanized in the freezer inside a sealable plastic bag. I have heard of this being done with slugs. Its said to be relatively humane.
If any insecticide and hair spray got on the tomato fruit, I dont recommend eating it. Spray tends to drift on the air and doesnt always end up where youre aiming. Sprayed fruit would likely have a nasty taste and insecticides can make people sick.
Insecticidal soap will kill hornworms. But it needs great care. Its harmful in eyes and mustnt get on tomato fruit. A substance called Btk will work on hornworms when theyre small and young. You can find both in garden centres.
Be sure to thoroughly dig the tomato soil this winter. Hornworm cocoons overwinter in the soil.
Anne Marrison is happy to answer garden questions. Send them to [email protected].
