|The two mini-greenhouses|
They are made of PVC stetched over metal frames. I have had them for several years and they have turned out to be really useful. You can buy them for about £15 in any good garden centre at the "right" time of year, meaning the times when most gardeners are thinking about acquiring some crop-protection - generally early Spring and late Summer - but they are seldom available in high Summer.
In the Spring I use them for "hardening off" young plants, giving them a bit of shelter from cold winds and heavy rain whilst allowing them to benefit from as much natural light as possible. Tiny seedlings often go stretched and "leggy" if you keep them indoors on a windowsill, because however assiduous you are with moving them around to follow the daylight they never get enough of it. You really need to get them outside. The mini greenhouses are ideal for this since you can move them around the garden if you haven't got a place that gets the light for most of the day. When I am at home I often shift mine in the middle of the day to ensure that the plants get both morning and afternoon light. A point to note though: although the plastic covering will stop any frost settling on the plants underneath it, the temperature inside the mini greenhouses won't be much different to the outside temperature -- just a degree or two at most -- so you still need to think carefully about what can survive and what can't.
The mini greenhouses come in a variety of different sizes. The ones I have are two-tier ones, but you can get three- and four-tier ones too. I think the taller ones might be a bit unstable, though they do come with anchor points on the back so that you can strap them to a wall. I sometimes have to weight-down even my two-tier ones with a few bricks to stop them being toppled over by the wind.
The various components are easily assembled and disassembled, so several different configurations are possible, and if space is scarce you can always pack them away when you're not using them. Wire mesh shelves are provided, along with rods to support them. When I am using the greenhouses to hold seed trays, which are quite shallow, I use both shelves, as shown in this next photo, but when I'm using bigger pots or containers I often omit the lower one and just place them on the ground rather than on the shelf. (Point to note: the supporting rods cannot be fitted or removed without first removing the cover.)
|Two shelves fitted, one with supporting rod, one without|
Later on, when some of the plants get quite tall, I remove both shelves and the supporting rods, to make a single taller unobstructed space, which is good for things like young tomato and chilli plants.
|A tall unobstructed space|
One unfortunate aspect of the design is that no matter what you do the top of the construction is bound to sag a bit, and does tend to collect rainwater. It ought to have a third hoop in the middle. Still, thinking positively, I see the extra weight the rainwater contributes as being just another aid to stability!
|The roof tends to sag|
Replacement plastic covers are available separately, though I don't think you can buy the metal frames separately. I am on my second set of replacement covers now (Each one has lasted 2 or 3 years). After a couple of years the PVC goes cloudy and brittle (and my first ones were savaged by cats wanting a bit of shelter and trying to get inside!). They cost about £5 each for the two-tier version, and are readily available on the internet. I got my most recent ones from a place called Garden Centre Online A point to note here is that it pays to shop around -- exactly the same product is often available from several suppliers at completely different prices, and NB: delivery charges vary enormously.
The PVC cover is attached to the frame with some fabric ties. The cover has a zipped front that can be rolled up and secured out of the way with another fabric tie.
|Zipped cover rolled up and secured|
I think these products are a very worthwhile investment, and I have used mine extensively.
Now that Autumn is coming on, I'm thinking about putting a few things under cover, and my "Son-of-Wilma" tomato plant will be one of these. I do hope it can produce some ripe fruits before the cold weather gets it.