Q: About two years ago I found a sprouting seed inside a red grapefruit. I had never seen that before so, just for fun, I planted it. It was slow getting started, but now I have a grapefruit tree of over three feet, and growing so vigorously it’s scary. It spends summers on the deck, and winters inside in a south-facing window, which is when it gets its new growth, for some reason. Anyway, I’m full of questions. How big will this tree get? Sooner or later I’ll have to trim it back, so how long can it survive as a house plant? And here’s the big one: Is there any chance it could produce fruit?
A: Good for you for getting the tree to the point it’s at now! Great idea letting it enjoy the summers outdoors, and that’s the perfect location in the south-facing window indoors. Just be careful that when you have it outdoors you give it a little protection against the sun on very hot days. The tree will get as big as you let it get. If you keep giving it larger pots and repotting it will continue to grow. Yes, you can control the growth through pruning just like any other fruit tree.
Depending on who you listen to, grapefruit trees take six to nine years to fruit. Citrus trees need to be fertilized to encourage them to bloom. Use a fertilizer intended for acid-loving plants and apply the fertilizer at half strength, and only when the tree is actively growing from April to August.
If you are lucky enough for it to bloom you will have to do the fertilizing. Use a cotton swab or artist’s brush to transfer the pollen from one flower to another. You might try making a buzzing sound while doing this. If the fertilization is successful, don’t be frustrated if the fruit drops off for the first year or two, this can happen.
Q: I’m having a real problem with cutworms and root maggots. The cutworms are going after all the veggies, while the root maggots are specifically attacking the onions. Is there anything I can do or use to get rid of these pests?
A: For controlling the cutworms there are several cultural methods you can use. You can pick the worms off by hand, but you will need a flashlight as they are active at night. You might want to alert your neighbours that you are being a cutworm commando just in case.
You can lay diatomaceous earth at the base of the plants. You can also place the diatomaceous earth in the rows when you are planting. This method would be effective against root maggots as well. Another method is placing collars around the base of the plants. Collars are available from most garden centres.
You can also control the pests biologically by watering vegetable transplants with nematodes. Another method involves using BTK, a naturally occurring bacterium that is known to cause illness in many insect larvae. It has no known toxic effects on humans, other mammals, plants, birds, fish, honeybees, or other beneficial insects. Apply the BTK liberally to the base of the stems. You will need to repeat the application frequently. Please note that this method will not control cutworms below the soil. Best of luck!
The longer I write this column the more I enjoy getting e-mails from readers just telling me stories. I also like sharing these stories. Here is one that put a smile on my face recently and comes from another spider lover:
“I loved your recent spider piece. It’s so true that these lovely creatures are a gardener’s best friend. I, too, use a duster or a dust mop for the errant spider to hitch onto. We’re a catch and release household for everything, although I read that basement spiders are not ‘lost.’ Apparently they don’t live long outside. They’re best left where they are because ‘they have spider work to do.'”
Thanks for sending in your stories, and I should note that the big fat white-yellow ones on the peonies are my favourites. Good luck and happy gardening!
Gerald Filipski is a member of the Garden Writers of America. He is the author of Just Ask Jerry. E-mail your questions to firstname.lastname@example.org . To read previous columns, go to edmontonjournal.com/author/geraldfilipski
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