The buzz on hand pollination, large-scale citrus setbacks, and the mystery of the missing broad bean pods.

Your questions answered

Do you have a food-growing question you’d like me to answer? Check out these guidelines to find out the best way to ask.

A possible pollination problem?

I grow most of my summer vegetables from seed, starting them off in my brand-new greenhouse. Now as l am in a wheelchair l am using pots and the solar-powered Verti Gro system in my greenhouse. l will also plant outside in the food cubes and in pots, and gradually in the garden. Some zucchini, summer squash and tomatoes l will keep in the greenhouse system.

My question is how do l hand pollinate these plants? I have noticed a couple of flowers on the zucchini, and the tomatoes are getting ready to flower.

Nola Y., Doreen, Victoria

This is a great question, and I’m asked it often. I grow tomatoes under insect netting. It provides a great microclimate and helps to extend the season. It prevents the birds from eating the fruit and it stops the dreaded Queensland Fruit Fly from stinging the fruit. However, my set-up also prevents bees and other pollinators from accessing the tomato flowers. And guess what? I still pick crates and crates of tomatoes every year. Tomato flowers seem to pollinate themselves just fine, which is probably why they come out true to type when you save their seed.

I’m not so sure about the cucurbits though. The zucchini and cucumbers may need a little help. I don’t usually grow such things in a greenhouse. In the handful of times that I tried it, I found that the humidity usually led to too many pest and disease issues to make it worthwhile. If it were me, I’d wait to see whether there is a pollination issue in the first place. Once it heats up a bit more in summer, you’ll probably find that you’ll need to open the doors of the greenhouse, or somehow increase ventilation. This might allow access for the bees to render their services. If a pollination problem emerges (or you don’t want to risk it) then you can hand pollinate using this method.

I’m keen to hear how you get on with the greenhouse this summer. Some folks swear by them and others have similar problems to what I’ve experienced (more on my experience with greenhouses here). I think it comes down to the specifics of the greenhouse set-up.

What’s your take on growing food in a greenhouse? Have you tried it and got any tips to share with Nola?

A simple solution for scale

In response to my recent blog post on Growing Citrus in a Cool Temperate Climate, Rose from Gembrook in Victoria wrote:

Worst citrus pest – scale insects, and the Argentine ants that bring them and farm them. Keeping the ants off is quite tricky. Have tried sticky bands and 'Tanglefoot' [a sticky barrier product] with very limited success. I may need to spray with white oil more often, which I don't like doing.

Scale is a common pest of citrus trees. You’ll find many recommendations for how to treat them. But I’ve noticed that most citrus trees suffering from scale all have something in common.