Do Autumn Veg Plants need a Greenhouse?

With our Autumn Plants now available to pre-order (with delivery from late-August through to mid/late-October), we’ve received a number of queries from customers wondering if they will need to be grown in a greenhouse/polytunnel or not. We have 5 points to make on this:

  1. As a general rule, you can plant all autumn plants outside – they are all fairly hardy, and should withstand light frosts. That said, it is wise to cover with horticultural fleece or a cloche if the forecast is for heavy frosts/snow. It is also really good to mulch, to help retain warmth in the soil.
  2. One exception to this is beetroot – we would advise planting beetroot in a greenhouse/polytunnel, or covering with a cloche from mid-September.
  3. If you do have a greenhouse or polytunnel, the added protection from winter weather – hail/heavy rain/frost/snow – will be beneficial to ALL the plants. If you don’t have space to grow all the plants under cover, then choose the more vulnerable or slower growing plants: Beetroot, Winter Lettuces, Wild Rocket, Winter Purslane, Corn Salad (and Curly Kale which can be slower to grow than the taller varieties)
  4. Daylight is a critical component – if your greenhouse or polytunnel fall under shade during the daylight hours in winter (they may get full sun all day in summer when the sun is higher, but sunshine may be blocked by trees/buildings during winter) then it is a bit of a toss-up between the warmth of the greenhouse vs the sunlight of an outdoor patch in your plot. In this instance, we’d probably opt for planting outside but covering with fleece.
  5. The milder your climate, the less need for protection – you will most likely find it easier to grow autumn/winter crops outside if you live in Cornwall or Devon rather than Northumbria or Scotland. A greenhouse or polytunnel would be great if you live further north where daylight hours and climate are slightly less favourable. If not, then perhaps think about building a hoop frame to cover raised beds with polythene to help provide a little extra warmth.

One last top tip:

If you can, plant half your autumn plug plants in your greenhouse/polytunnel, and the other half outside. This will give you a more staggered crop when it comes to harvesting your produce.