I’m a lucky duck – I have a big veggie garden and a greenhouse. The greenhouse was converted by our builder from an old tool shed. He removed the old tin sheets, and replaced with poly sheeting and white shade cloth for ventilation. Doing this mini-renovation on the old shed, which we were going to remove anyway, saved us about five thousand bucks and has created a much more sturdy and larger greenhouse than we could have had if I purchased a flat pack model online (which was my original intention). Thank goodness for innovative builders!
I love it. I mean, I love it. I can’t wait to go outside every morning to water it and see what has happened inside over the past 24 hours. I’m obsessed.
I grow almost all edible plants in the greenhouse, with the exception of a few ornamental cuttings I am striking. Aside from that, it is an oasis of fruiting plants and vegetables, especially this time of year.
But it’s also been a bit tricky to learn how to manage the greenhouse, compared to growing outside in the open. Last year, which was my first Summer with the greenhouse, I was inundated with aphids and it was not a fun time. I left it too late to treat them, and I could not stop the invasion. This is because I was used to growing outside in a very large space, where a bug here or there doesn’t matter much. Everything balances out. But in the greenhouse, which is its own little micro-climate, things don’t balance in the same way. It’s warm and humid, and the aphids and white fly just love it. Predators do come in, but they are also busy outside, where there are more flowers and other plants for them to work away on.
This year, I have been much more proactive. I keep yellow sticky strips in the greenhouse all year round, which has helped to keep the population of whitefly down. I have noticed that the whitefly attract the aphids, so keeping their population down helps. When I water, I keep an eye out for both, and if I see them I either squish them or give them a quick squirt with the hose as soon as I see them. If they still proliferate, that is when I spray. I found out the hard way that the recommended homemade soap spray (water mixed with dishwashing detergent and a little cooking oil) is fine in the open garden, but burns and kills plants in the greenhouse, due to the soap and oil hitting tender leaves in an environment of high heat and humidity. In addition to the hosing and squishing, I have been trying a homemade spray made of chopped tomato leaves soaked in water. That has been quite successful.
Soak tomato leaves in a bucket of water for several hours, up to overnight. I just filled the bucket with a many leaves as I was willing to pull off the tomato bushes and then topped up with water, then left to soak. Strain and pour into a spray bottle. I have found that the aphids steer clear, when combined with hosing them off pretty regularly.
The other pests I have struggled with recently is spider mites. These little buggers are much worse than aphids, as you can’t see them with the naked eye and you don’t notice you have them until the leaves of your plant start to show the telltale signs of damage (silvery leaves, tiny webs). I hate these jerks. They are really hard to get rid of and they spread quickly. A soap spray is the recommended treatment, but as I have already mentioned, in a greenhouse that is problematic. I have to choose a very cool day and hope for the best, or if the plant is too far gone, put it in the green bin.
Watering the greenhouse
Watering the greenhouse is a big job. While you can get away with skipping a day or two in the patch in hot weather, you can’t in the greenhouse. It is several degrees hotter in there, and everything is in containers. They must be watered or they will die. Simple as that.
When there were fewer pots in the greenhouse, I could manage with a couple of watering cans. Now, I need to use a watering gun and hose. We spent about $40 on a strong steel and brass watering gun, with the hope that it will last quite a few years, and now watering takes about ten minutes instead of half an hour – and I am not lifting heavy cans of water.
Be careful with saucers in the greenhouse as well. I have found that in they are susceptible to algae growth due to the higher humidity. While saucers may be preferable when growing containers on balconies or patios, I have mostly removed them in the greenhouse.
Pollination
Pollinators do come into the greenhouse – it’s not hermetically sealed (so do birds, and I think some other critters, judging by a couple of overturned pots I have found). I have spotted native bees and hoverflies in there several times. But my open veggie patch is a pollinator’s paradise, thanks to all the herbs and flowers I plant, and my mini-meadow. So the greenhouse gets short shrift from pollinators.
Things still fruit in there, but I needed to think about how I can increase pollination rates. I have came up with a few solutions.
The first is hand pollination of cucumbers and zucchini. This is easy: just strip off the petals of a male flower (the one without the swelling at the base) to expose the pollen filled stamens, and poke it in the female flower a couple of times. Some people are much fancier than me and use a paintbrush to delicately remove the pollen from the male flowers and dip it into the female flowers. You can do that if you like. I’m a little less refined than that.
The other thing I do is mimic the buzz/wind pollination process for tomatoes and related plants. Tomatoes are self-fertile but require wind or the visit of a busy bee to buzz alongside them and shake their pollen loose. The greenhouse is not as exposed to wind, and while bees do visit, most of them are buzzing around the borage outside. To address this, I have a cheap electric toothbrush (sans brush). I have taped up the poky end so as not to accidentally stab myself, and I gently buzz the top of each tomato flower. I don’t want to brag, but I can see the little puffs of pollen shake loose when I do this, so I think I am easily as good as a bee at this job.
Of course, it’s hard to explain to others. Like when my sister called and asked what that buzzing noise is. And I had to admit what I was actually doing. She said it sounded like the world’s most boring porno.
With all this effort, is it worth having a greenhouse?
I’m not going to lie, a greenhouse is an expensive exercise. Firstly, there’s the expense of building it in the first place. Then there’s the set up. This can be minimised in a couple of ways. We did this by converting the old toolshed, as I mentioned, and by recycling pots and shelving. We did buy some shelving and raised troughs online, but we have also sourced a lot of pots, shelving, and stands from our local Buy Nothing Group on Facebook. That has reduced the cost significantly, but there are still other expenses, such as the potting mix, water, and time. I can’t pretend it’s not a luxury, or that my five cucumbers yesterday couldn’t have been purchased yesterday for much cheaper than it cost me to grow them. However, once the greenhouse is built, and all the pots and shelves are in place, they can be reused almost indefinitely. The cost of the set up is spread over years, and the value will be maintained. The ongoing expenses of potting mix, water and time will remain.
Growing plants from seed also reduces the amount of plants I buy in seedling form, which does save money – so long as I resist spending too much on seeds. I can grow almost anything from seed in just a couple of weeks, which is amazing. 95% of the veggie garden this season has been grown from seed. That is so exciting to me, as a gardenerd and obsessive.
Aside from the fun, I can see the difference in plant size and productivity between plants in the greenhouse and in the open garden. I have cucumbers I planted in the greenhouse and in the garden at the same time. I am picking cukes from the greenhouse while the cucumbers I planted in the garden are still having a little chat with each other about whether they might possibly consider growing another millimetre this week. I have eggplant flowering in the greenhouse, while the eggplant in the garden are having a little stretch. It’s not that they can’t grow, it’s just that the weather is still so unpredictable this season, they are not sure why they should. Whereas the greenhouse, with its stable lovely warmth is just so conducive to growth.
So is it worth it? For me, it is, simply because gardening is my main hobby and great pleasure in life. Some people love cars, or music, or movies, or art. I love plants. If I had all the free time in the world, I would spend it in the garden. In real terms, it is a relatively cheap, and certainly an active and healthy hobby. I just wouldn’t suggest a greenhouse unless you have the space, money, and time to spend troubleshooting the challenges that can arise.
