I can't believe I am already writing about the vegetable garden in August, where has all that time gone? I don't know what the weather is like where you are but we are seeing cooler, showery days which may not be great for the beach but are very welcome for the garden. I was surprised at how much the soil dried out in the hot weather in July, especially over such a short period of time. Of course there are some crops that will enjoy high temperatures but there are plenty of others that don't.
If you are growing any member of the brassica or cabbage family including autumn or winter cabbages, cauliflower, calabrese, purple sprouting broccoli or Brussels sprouts, they will be much happier in damp August weather and will show a growth spurt now there is more moisture in the soil. Maincrop potatoes will also be bulking up now which is when they need the most water to produce a good crop so let's not get upset about the rain, it is just what the garden needs.
This week I give you my list of what to sow and grow in August. I have also included my usual update from my garden with plenty of photos, I hope you find some of it helpful and relevant to your own vegetable garden.
The Vegetable Garden in August
August is more about harvesting than sowing but there are a number of new crops which will do very well in cool Autumn weather or can be sown for overwintering. I have had a very disappointing year so far with annual spinach as the hot July weather caused it to bolt but, if sown in August, you are almost guaranteed a succulent and leafy crop. Oriental salads will also run to seed earlier in the year so will be much better in August and September with the advantage that their cold hardiness keep them producing into November outside, later under cover.
Don't forget the large winter radishes ('Watermelon above) or turnip either that are fast growing and add a sweetness to winter trays of roasted vegetables. Spring cabbage is also easily forgotten but needs to be sown in August to produce juicy pointed cabbage heads next April when you will be glad of some fresh greens. The Autumn sowing list may be small but there is still plenty to celebrate!
What to sow for outdoor growing: Lettuce Spring Onions Radish Turnip Annual Spinach Oriental salads Winter salads Spring cabbage Winter radish
What to sow for the greenhouse or polytunnel All of the above plus: Calabrese Chard Chinese cabbage Florence fennel Parsley Beetroot
Harvesting Sweetcorn I had my first sweetcorn harvest of the season at the weekend which is a little earlier than usual thanks to the hot weather we had in mid July. Once the silks or tassels begin to turn brown, it is a sign that the kernels are beginning to ripen and your cue to start watering if the weather is dry to ensure sweet and juicy cobs.
Sweetcorn ripens in stages over a period of about 4 weeks. In the early stages the kernels are a milky yellow colour with a flavour more like baby corn but after 2 weeks, the cobs turn bright yellow and are at their sweetest. If left to mature for a further 2 weeks the kernels turn a darker yellow, like a good egg yolk and become more chewy but less sweet.
The time at which you harvest is obviously down to your preference; to check progress you can peel back a small portion of the cob to check the colour. You can also check ripeness by puncturing one of the kernels with your nail, if a clear liquid squirts out the corn is immature, if it's milky it's about right.
Personally I prefer corn at the mid point when at its sweetest and juiciest. Peeling back the sheaf of the first cob (pictured above) is always an exciting moment when you see if the all the kernels have been pollinated (there will be gaps if they haven't) and very satisfying when you get a full ear of corn. Absolutely nothing prepares you for the flavour, I intended to bring the cob into the kitchen so show my wife but didn't even make it out of the tunnel, it you don't have strong willpower, don't take a bite.
Growing Squash I have planted a number of squash varieties in the polytunnel for the vegetable course video project I am working on and am beginning to regret it because they are starting to take up so much room. The photo above is them just getting started, they will take over the whole tunnel if I let them.
I will start to restrict them somewhat in the next 2 weeks. Once I know that I have enough fruit set, I will either stop (cut off the growing tip of the vine 2 or 3 leaves past the last fruit) or remove some of the vines altogether. In order to get decent sized fruit from a squash or pumpkin plant it is best to limit the number of fruit to 2 or 3 for pumpkins or large squash or 4-5 for smaller varieties depending on how long your growing season is. I am growing in the tunnel so might stretch that a bit as I have a longer tail end to the season but the above applies to outdoor growing in all but the warmest, most southerly gardens.
The image above is a squash 'Crown Prince' fruit which is putting on weight nicely. I give the plants a really good soaking once a week in mixed weather, twice a week if it is hot and sunny. Like most vegetables, squash has a high water content (85%) so indoor plants need to be kept well irrigated to produce well, they also have a huge amount of leaf so lose a lot of moisture through transpiration.
After our article on tomato plants last week, I had a number of mails about squash or courgette plants failing to fruit. Unless temperatures are too high (only likely if grown under cover) the other most common problem will be pollination. This may be more likely in wet weather as there are less flying insects about when it rains so you may need to pollinate them yourself.
You can tell the male and female flower apart as the male has a skinny stem while the female has a bulge (immature fruit) behind the flower. If the flower isn't pollinated the baby fruit will drop off. I think I covered this before in April but here's a few new photos from yesterday morning anyway. Above you can see me taking pollen from a male flower (with one of my daughters' make up brushes), notice that the male flower has a single stamen in the middle of the flower.
In this picture you can see the immature fruit behind the female flower and me transferring the pollen to the stigma in the centre of the flower. You will notice that the stigma is made up of multiple parts rather than the single stamen on the male flower, another way to tell them apart. Just for clarity, I have removed half of the petals so you can see what I am doing, it was originally a full flower.
Stopping tomatoes Just as I will be doing with my squash, I will also be 'stopping' some of my tomato plants as they have reached the tops of their supports and I want to make sure that all the green or developing fruit ripens by the time we reach October when it gets too cold for growth and the plants are removed.
I have been removing side shoots all along to restrict growth to one single vine but never the growing tip of the main stem as, until now, I wanted it to continue growing up the support twine but it has now reached the roof of the tunnel. I have left this top unpruned so you can see the difference; we have two side shoots either side of the main stem (in the crook between the stem and leaf set) and the main stem running up the middle. I will cut the top of the middle stem and, as I have been doing all along, prune out any side shoots otherwise they will produce a new main stem.
You may think it is a waste to cut off the top of a plant which is happy to grow on and produce more flowers but, unless the earth turns significantly on its axis, they will be unlikely to ripen. Bear in mind that at this stage of the season, you probably have only a third of the fruit on your plants ripening (as above) so there is still plenty of existing green fruit to go.
Staggering French bean harvests This is a bit of an excuse to show some of the beautiful colours in the vegetable garden, above are my French bean 'borlotto lingua di fuoco' (tongue of fire for any budding linguists out there) showing their characteristic vivid magenta speckled pods. I am growing the borlotto beans for drying so they still have a while to ripen on the vine but the climbing bean 'Cobra', after providing multiple harvests since mid June, are now finished so I'm removing the plants to make way for a new crop.
The point is that while one crop finishes, another is just beginning. This photo is of dwarf French bean 'Purple Teepee' which I sowed about 4 weeks ago and is just beginning to flower now. I would expect to begin harvesting beans towards the end of August and will continue to pick into October.
I grow French beans in the polytunnel as I don't have the climate to grow outside and sow my second crop of beans relatively late in early July because I have an extended season undercover. If you are growing a second crop of French beans outside, a mid June sowing is probably best, too late for this year of course but a handy tip for next season.
Brussels Sprouts - Staking and cabbage white butterfly I have two plantings of Brussels sprouts on the go this year to give me an early winter crop followed by another coming 4 weeks later to bring us through to January. The first lot was sown on the 1st of April, the second, in the foreground, on the 4th of May, despite the leaves being a different colour, they are the same variety, 'Brigitte F1' which is an absolutely superb sprout.
I include them here as a reminder of what big plants they are and why, in my opinion, it is important to stake them before autumn winds try to knock them over. I notice some commentators view staking as optional which I don't agree with because of the increased chance of blown sprouts.
A blown sprout is when a sprout opens like a mini cabbage rather than keeping its tight button shape, a problem more common with older varieties but also caused by lack of feed or roots being broken due to wind rock. A tough sprout plant may look OK after a stormy night because it's anchoring roots have held it firm but if it is leaning, many of the roots on the windward side will have been broken.
We need to remember that any plant root consists of the relatively large roots that we see but also a huge network of hair thin feeding roots that are easily broken. Damaged root hairs put the plant under stress which can trigger sprouts to open or 'blow'. The way I look at it, if you've spent so much time growing the thing (since April), would you not just support it with a stake to make sure?
You need to use something heavier than a bamboo, an inch square stake will be fine. The image above isn't of blown sprouts, just to be clear, but the first buds of my sprout harvest developing on my early sown plants.
Cabbage White Butterfly We are now coming into the time of year when cabbage white butterflies (or more accurately, their caterpillars) will be a problem on any member of the cabbage family, they are particularly annoying on Brussels sprouts as they have so many leaves and therefore so many egg laying sites. The cabbage white caterpillar has a hearty appetite which grows at the same alarming rate as he does and can result in completely denuded plants in a matter of days.
There are two cabbage white species, the small and the large. The large butterfly lays clusters of yellow eggs under leaves as shown above. Believe me, it is much easier to rub off or squish these tiny eggs with your thumb rather than have to deal with the caterpillars. The small white is more tricky to deal with as they lay single bright green eggs which are more difficult to spot.
Netting with insect protection mesh is an option but difficult with sprouts as they are so big. You can also spray with the natural solution Bacillus Thurengiensis but it is hard to get as a retail pack (I can't get it myself) so unless you are growing a field of sprouts, the thumb might be the only answer.
Harvesting and storing onions or shallots If you are growing maincrop onions, they will be coming close to harvest time now which you will notice by the foliage turning yellow and starting to lean over. Shallots are usually 3 weeks ahead of onions so should be lifted and be drying by now. Another wonderful colour above, this time onion 'Long Red Florence', a beautifully sweet torpedo shaped onion that I highly recommend.
The harvesting method differs slightly for onions and shallots; with shallots, once the foliage had fallen they should be lifted straight away while onions should be left in the ground for another 10 days or so before pulling. In a wet August, the maturing process can be delayed and result in onions rotting in the ground do you may need to intervene to help things along. I used to bend over the stalk but I read many years ago in Klaus Laitenberger's excellent book that this can lead to rot in storage and the better method is pulling gently to break some, but not all, of the roots. I have been doing this since and can confirm that it works very well.
Once the onions have been pulled they should left out on the soil to dry in the sun (what sun?) for a further 10 days before being processed for storage. As August can be wet it may be necessary to bring them inside to dry, in my case (above) in the tunnel (those are shallots above with the unruly squash behind). If you are drying onions or shallots in a greenhouse or polytunnel be prepared to bring them outside in sunny weather as exposure to high temperatures in the tunnel can shorten their storage life.
It is important to leave the foliage on the onions while drying as this will improve their storage potential. They are also handy for stringing up your harvest. I am not very good at the traditional method of plaiting onions or garlic, the results never look like the neat braids you see on people's blogs but stringing them up with twine is really easy.
You only need a length of twine with the ends tied together and suspended on a nail or whatever is handy to form 2 parallel lines. The dried onion or garlic leaves are simply wound around the twine, it takes no time at all but looks reasonably accomplished when you are finished. It's difficult to describe in words and I did make a new video the other day but, until is is edited, you can watch one we did many years ago now if you'd like to see the method on screen.
See you next week! That's about it for this week, I hope the above was helpful to some new growers out there, as usual, let me know if there is any topic you would like me to cover over the rest of the summer.
See you next week