Wednesday, January 19, 2022
Jan. 19, 2022

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Ask the gardening expert

The Columbian

Hello, we have a large, high tunnel and planted it for the first time this year. The corn grew tall and spindly, and the cobs were half developed.

They were well-watered and fertilized. Any thoughts as to why it would do that and a solution?

— Tim

Wow! what a nice structure. It’s gorgeous in fact.

I’ve never heard the term ‘high tunnel’ before. Maybe I retired too soon.

However, I’m at a loss as to why you wanted to grow corn in there.

Corn needs all the sun and fresh air it can get.

The structure is keeping it from the wind and air circulation, plus the pollinating insects are not as likely to find the crop in there.

I’m sure it seems bright in there to you and me but it’s not bright enough for a healthy crop of corn.

I don’t think there is a thing wrong with the corn — or the greenhouse for that matter. It just that corn would get all its growing needs met in the outdoors, with Mom Nature looking after it.

I remember you said that you have a greenhouse.

What do you keep in there in winter? How warm does it need to be in winter?

I do not know what is recommended, so I am running mine as I see fit.

So far so good. (Another opinion thing, I guess) this is going into the third winter,As summer draws to a close, I am deciding what to keep — and what goes into the compost bin. I have some 3-year-old zonal geraniums (eight of them) and 5-year-old wing begonia (five of them). Daughter Jen has several ‘ivy’ leafed begonia that she doesn’t want to give up on. They are amazing performers in our summer deck display.First, I’d give a close and through inspection. I don’t want insects and diseased plant parts brought in to the greenhouse.

I begin by cutting the plants back severely, repotting if necessary. I water everything really well, and then the plants them do their thing until next spring.

The geraniums start blooming right away before winter. The Dragon Wing will too; it has nice color in winter.

I keep the greenhouse between 45 and 50 degrees all winter if I can. I’ve placed small fans on either end of the house aimed toward the roof. They are going rather slowly — just to keep the air moving.

I had two sun gold tomatoes supplying us nearly all winter. I have two grafted tomatoes blooming like mad in there — along with the seedling sun golds.

Celeste Lindsay is a WSU-certified master gardener. Send questions to