lights are a very expensive option, even in the PNW. Is there a tree you can remove, or could you build on the roof of your house?

Having a greenhouse is still better than not having one, even if you don't have the optimal conditions. Ideally you want SW exposure with full winter sun, but a second choice is to have morning sun (jump starts plants in the AM). But even if you have only evening sun, you will still be able to grow more with a greenhouse than without. Also, a diffused covering will make the best use of the light you do have.

There are some new lights, called T-5 that have very good output and are fairly inexpensive to operate, although the fixtures are an investment. Grow lights can make a huge difference, expecailly in northern climates when the days are so short. Some vegetables require 12 hours of light to produce.

Another good option is to use heat mats. Since you won't have all of the solar heat, you may want to add bottom heat to your plants. This will keep the roots warm and you won't have to add heat to the entire greenhouse if you are growing cool crops.

I have just joined this wonderful forum(s) and have been going through the greenhouse postings because I am going to (I think) build one this year. So much great information and ideas! I have had two GHs in the past but both in Ontario where winters are cold and sunny (at least come January).

My concern here on this Gulf island in BC (49 degrees lat.; 140 miles north of Seattle) is similar to Perry's: no winter sun. Not because of trees blocking it, but because the sun simply doesn't come out here in the winter! Okay, on the very odd occasion it does in a rather pathetic fashion but this is rare.

We have actually had a few sunny afternoons in the past 10 days (glorious!!!). But I am wondering about greenhouses here. I am wanting to overwinter herbs, grow salad greens and such, and extend the growing season generally.

Have you decided to go ahead with a greenhouse, Perry? I'll be monitoring the sun over the next couple of months but how do others in the cloudy PNW do with greenhouses from the perspective of light?

I appreciate any input!

April

April, Perry:

I'm in the northeast but I have a similar sun problem. This is my first winter with a greenhouse and what I've found so far is that while my plants lived and grew they didn't do as well as those in greenhouses with lots of sun. For myself I will be adding lights next year. This may be an option you'll have to consider but you could probably limit it to those plants you want to flower.
I was reading a gardening book this weekend and they suggested adding mirrors to the north wall for reflected light. I don't know how good an idea this is but I thought I'd toss it out and see what others thought.

MollyD

In the PNW, we go weeks with no sun at all. Late Jan and Feb often have sunny days but Nov, Dec, Mar, April and often May are often grey and/or raining.

I don't think winter growing without lights is possible here.
Especially if the greenhouse doesn't have unobstructed sun.

Mine is in a lot of shade and I don't have lights yet and I have kept my tropicals from freezing to death but there is no growth except a few pale stretched out leaves on the cannas.

A friend of mine bought high pressure sodium security lights at Lowes for $69. Her husband removed the dusk to dawn sensors and she is using them in her greenhouse.

Not traditional greenhouse fixtures at all but she says they work. She doesn't live here so I haven't seen more than pictures but she's had her greenhouse for years and grows orchids and other tropicals, including tropical waterlilies in her greenhouse pond. She has one light hanging right over the pond.

The cheapest tradional greenhouse HPS lights I have found are $300 even for a small 6 x 8. I think anything that is labeled "greenhouse" like anything labeled "pond" is higher priced!

DH and I will be trying the lights from Lowes.....

You're right about that buyorsell!! I recently bought a ProCom heater at Home Depot labelled for in house use. Later I saw the same exact model in a greenhouse catalog at about $60.00 more!!
Go for the Lowe's lights. If they don't work for you at least you won't be out too much money. How hot do they get btw? Will they burn your plant leaves if they're too close? I've never worked with sodium lights.

MollyD

Something you might want to consider if you have room in a basement, spare bedroom, etc., is growing indoors under lights at least for the winter. I have an extra bedroom with a 400 watt Hydrofarm Radiant Agrosun metal halide light that I use to overwinter my tropicals, mostly hibiscus. They do fairly well, although they don't bloom much - too many plants for the amount of light I have. If I were to do it again, I would buy a 1000 watt, which should cover about a 10x10 foot area. A 1000 watt high pressure sodium fixture would be ideal for a greenhouse of that size. Your Lowe's lights will help some but not enough wattage to make a big difference.

Farmtek sells some reasonably priced greenhouse lights, but I bought the Radiant because it has a glass shield, which gives me a little extra peace of mind about fire safety in my home.

I have also grown under fluorescent lights on and off for 40 years. I currently have cheap T8 shop lights and find that they burn out quickly. I am considering a nice T5 setup from a seller on ebay that some of the orchid forum folks recommend. Still not cheap though.

The problem with any fluorescent tubes is that you must hang them very close to your plants (within a few inches) to maximize the light. But they you are effectively blocking most of the available sunlight (should you have any). So you might as well grow indoors and save money on heating. I would love a greenhouse, but the cost to heat one for the winter in Maryland would be way more than several nice grow lights.

If you want more details, email me or visit the growing under lights forum.

Greetings,

I am wondering what those of you who said you couldn't grow things in the winter were trying to grow? Tropicals? Salad greens? As much as I would love to grow tropicals, I don't even bother to aspire to it. I want to grow lettuce and such and overwinter herbs and I don't want to use a lot of energy heating it. This is 8'x10' with twinwall that I am thinking of.

But I really don't want to go to the expense and effort of building a greenhouse and having it not work because of the climate here in the PNW. (Not to mention having an unusable greenhouse plunked right there!) I know that a solar greenhouse is not advisable in the PNW. I am just hoping that a regular one is!

April

I'm in zone 4b and I grow daylilies. They're not tropical but require about a minimum of 55 for the babies. These are not adult plants (except for 3 of them) but rather seedlings. I use my greenhouse to get a headstart in growing them since our growing season is so short. My heat is set to run up to 65 then off.

MollyD

My greenhouse is for tropicals but right now it is stuffed full of anything tender since we got really cold weather very early here. We usually aren't nearly as cold as we were this year. Usually just grey and raining.

People in other parts of the country just can't understand how grey and rainy Seattle and Portland really are. I would not have known how bad it is except I grew up in Arizona.