We always get loads of calls in August / September looking for overwintering vegetable seedlings. Of course I'm delighted as we do a great range of vegetables for autumn planting from our online nursery but I often think many novice gardeners have unrealistic expectations from overwinter planting.
When temperatures drop and the soil cools below 5 degrees celsius in November there won't be any growth until March / April the following Spring. As little or no growth occurs in mid winter it's all about either planting in Autumn to harvest in winter or planting to harvest the following Spring.
Beginner vegetable gardeners may not realise that although brussels sprouts, leeks and parsnips are traditionally Winter vegetables they are actually sown much earlier in the year. Fear not though, there are still plenty of vegetables to grow, I've listed my personal top 10 below but you can view our full range of our vegetables to sow in Autumn in our vegetable seedling section here.
Autumn / Winter Vegetables August and September are still very productive months in the vegetable garden with growth slowing considerably in October only to grind pretty much to a halt in November. Unless you have a greenhouse or polytunnel (which I'd highly recommend) once the Winter sets in there won't be any growth outside with short days and cold temperatures.
There are really 3 main groups of autumn winter vegetables and it's handy to understand the plan here and the plants which fall into the three groups:
Autumn Vegetables The idea with Autumn vegetables is to plant quick growing crops that are ready to harvest before growth stops around mid November. Autumn garden plants like quick growing turnips, salads, spinach and radish can be planted in August/September and will provide a worthwhile crop and are handy to make use of otherwise bare ground following a previous harvest.
Autumn Planted Overwintering Vegetables Overwintering vegetables are planted in the early Autumn and will spend the Winter dormant in the ground to (hopefully) spring back into life when temperatures increase again in March and April. Crops in this category include Spring Cabbage, Autumn planted garlic, Autumn onion sets and Swiss Chard. You can also overwinter broad beans and peas for a crop about a month before your neighbours if you are of an impatient disposition.
Spring Planted Overwintering Vegetables Spring planted overwinter vegetables tend to be the ones everyone thinks of as and the ones novice growers usually get caught out on. These crops have a long growing season and are ready in the winter months but require a bit of forward planning to have them ready in time. Sprouts, for example will need to be sown before the end of April to ensure you can force feed them to your family and friends at Christmas time while the latest you can sow leeks is mid June though you probably don't think of them until the Autumn.
My top 10 below refers Autumn Vegetables and Autumn planted overwintering vegetables, we'll deal with (and remind you if you follow us on facebook) the Spring planted varieties in a later post.
My Top 10 Vegetables to Grow Over Winter
Garlic - Overwinter Growing garlic is really very easy, just plant the a clove in the ground and without much intervention you should end up with a full bulb the following Autumn. A garlic plant needs a period of about 6 weeks of temperatures below 10 degrees celsius for the clove to multiply to form a bulb which is why it's perfect to plant in the Autumn.
Planting garlic is best done from Autumn to early Spring with the Autumn planted cloves having a better yield. If you live in areas of high rainfall (who doesn't?) raised beds are recommend or delay planting until Spring.
We love our garlic here and stock a number of varieties suitable for Autumn planting, you can view our garlic and onion section here.
Spring Cabbage - Overwinter Spring Cabbage plants are planted in the autumn for a harvest of tasty conical shaped heads the following spring. Spring cabbage is sown in July to mid August and overwintered till the following Spring. Keep and eye out for slugs in a mild winter as although slug activity will be reduced in the winter they can still wipe out your new seedlings.
Sowing indoors in modular trays is most successful with 4 week old spring cabbage plants planted out 3-4 weeks later. Sow 1 seed per module at about 1.5cm deep and water well. If you've missed the sowing date you can access of Autumn / Winter seedling 'plants by post' here.
Broad Beans - Overwinter Broad beans can be planted in the Autumn or the Spring depending on the variety. We find Aquadulce Claudia to be the best for Autumn planting and can sown from September until early November for harvesting a month earlier than a Spring sown crop. Another advantage of sowing Winter broad beans is the plants protect the soil that would normally be exposed to wet Winter weather in the same manner as green manures. Sow directly in drills 5cm deep at a spacing of 15cm between plants and 45cm between rows. You can also sow indoors in modular trays, planting broad beans out 3 weeks later. It's also worth staking your plants as they can be buffeted about in Winter winds. Place stakes about a metre apart and join with twine to create a bean support frame as per image.
Kale - Overwinter Kale is a bit of an underrated plant as it's very easy to grow, highly nutritious and, if cooked properly (stir fry with lemon and tahini), a delicious vegetable. It is a tough customer and can easily survive the harshest Winter. If your plants are large enough you will get some useful winter greens but the main reward is when your kale plants get back into action in spring when there is little else in the garden. Growing kale is relatively trouble free
Grow kale in modular trays as they seem to do much better than direct sown plants. Sow 1 seed per cell 2cm deep but make sure they are planted out before the roots become restricted and pot bound. Kale should be sown by the end of June for planting out 3 weeks later. Don't worry if you've missed the sowing date as we have kale plants available in our winter seedling range.
Chard / Perpetual Spinach - Overwinter Chard is one of my favourite overwintering vegetables especially in the polytunnel where you can get a surprisingly long season. Growing chard is easy as it suffers from very few pests and diseases while producing new leaves as you pick them. Even outside chard will survive a cold winter and like kale will be one of the earliest sources of spring greens in your garden.
Some people are put off by the slightly bitter aftertaste of chard or perpetual spinach but this is where Autumn and overwinter planting are an advantage as chard is less bitter in the cooler months of the year.
Sow chard seeds 1 seed per cell in modular trays for planting out 3-4 weeks later. Chard seeds are actually clusters 3 or 4 seeds so any surplus seedlings that appear in each module will need to be weeded out to leave the strongest seedling.
Kohl Rabi - Autumn Vegetables Kohl Rabi is what Klaus Laitenberger calls the 'Queen of Vegetables', it's relatively unknown in Ireland but produces a fresh, slightly nutty tasting bulbous stem. It's relatively quick growing so makes it a good choice for an Autumn vegetables as long as you get your seedling plants planted in early August. If conditions go your way in Autumn you can get a very worthwhile crop outside while growing inside in a tunnel is ideal.
Sow Kohl Rabi in modular trays, 1 seed per module at approx 1.5 cm deep. Plant out 3-4 weeks later at a spacing of 30cm between plants and 30cm between rows.
Turnip - Autumn Vegetables When I say turnip here I'm talking about white turnip rather than swede turnip. If you choose a quick growing variety like speedy Tokyo cross you can get an excellent harvest of clean white roots before the Winter. Growing turnips is quick, easy and relatively trouble free and is a perfect follow on crop when any beds are left bare. Turnips make a delicious gratin baked with milk, cream, salt and pepper and topped with a little gruyere cheese, fantastic as the nights are drawing in!
I like to sow them in modular trays as I've got into the habit of sowing nearly everything that way but they are reliable and quick to germinate so perfect for sowing direct if you wish. Sow 1 seed per cell 1.5cm deep in modular trays or outside in drills 2cm deep at 10cm intervals. Thin drill sown crops to 25cm between turnip plants with a spacing of 30cm between rows.
Radish - Autumn Vegetables Radishes are so quick to mature, you can harvest roots from about 4 weeks after sowing which makes growing radish perfect for the last dash before the winter. I'll have to admit I was never a huge fan but have developed a bit of a taste for them by munching the little rosy 'Short top forcing' we grow in our Quickcrop seedling trays. The trick is to get them quick while still small for a lovely fresh peppery bite.
You can also sow Winter radishes like 'Black Spanish Round' which are sown in July or August for harvesting in October. They store well in boxes of sand or in a plastic bag at the bottom of the fridge. Winter radishes are slower growing and larger than the Summer varieties but are suitable for roasting or sauteing while smaller summer radishes are not.
Seed is best sown direct at about 2o cm between radish plants in rows 15 cm apart.
Onion and Spring Onion While we usually sow our onion seed or plant our onion sets in Spring there are still possibilities here for Autumn sowing. Growing onions from sets in Autumn results in an earlier harvest the following year but are not recommended if your garden is prone to water logging in Winter. Plant onion sets like Radar or Senshui yellow in Sept/Oct for harvesting in May.
Spring Onions can be sown until early August, later if you have polytunnel and will give you a good crop of crunchy onions. Most people sow weedy white lisbon which are my pet hate, try ishikura bunching instead for sure fire success.
Sow in modules with 8-10 seeds per module, plant each module at a spacing of 25 cm between bunches and 30cm between rows. When harvesting just pull up the whole bunch, cut all the ends to the same length and put a blue rubber band around them to pretend you bought them in a shop.
Oriental Salads In my opinion the real stars of the Autumn/Winter show are the Oriental salads because they grow much more successfully in cooler temperatures and are far less likely to bolt and run to seed than Summer sown plants. Orientals tend to be frost hardy and while they don’t enjoy being frozen they certainly tolerate it well. You need to have sown them by mid September to get a decent size plant by the time growth slows dramatically from November onwards.
You are in for a real treat with varieties like mustard golden frills and ruby streaks which has to be one of the tastiest salad leaves around and pretty much impossible to grow in the Summer. There are a huge range of oriental salads available as seeds from the Vegetable Seed Co. or a range of our favourite varieties as seedling plants. We’ve all tried rocket but have a go at prolific ‘mizuna’ and ‘mibuna’, tasty mustards including the hot and spicy ‘Green in the Snow’. Add bags of colour and flavour to your plate with these excellent end of year crops.
Vegetable seedling stuff