September 2014

September 2014

Autumn arrives, gardening priorities.

Clearing, last plantings, and composting or green manuring

As beds come empty, there are still some sowings to consider, mainly garlic from now until Christmas, and broad beans from November. Also if you sowed in August, some plantings of spring onion and spring cabbage. But I do not recommend autumn-panted onions for bulbing next summer, because often they harbour leaf-mildew which then risks infecting spring-sown onions, and also the bulbs store less well. Spring onions White Lisbon are genetically different (Allium cepa) compared to autumn-sown bulb onions (Allium fistulosum = hollow leaf) and Allium cepa appear not to host leaf mildew over winter, in my experience – I have not seen this written anywhere else but all the evidence I see in my garden and allotments bears it out.
If you are not planning to sow or plant vegetables before year’s end, a green manure I recommend is mustard Synapsis alba, fast growing and susceptible to moderate frost (around -6C  or lower), meaning there is no need to mulch or “dig it in”! In most winters it just leaves a straw mulch of its stems on the surface, easy to rake off. One thing though, I recommend weeding it to keep soil clean and prevent any seeding of weeds.

There is also Caliente mustard, a cultivar which has lots of biofumigant that works to suppress soil pests and diseases. The snag for this with no dig is that it is said to be most effective when chopped fine and then incorporated in the soil. I have not tried it yet.

And the final option is to spread compost, as a mulch and soil food overwinter, with less risk of slug proliferation.

Harvest time, and a film with lots of advice on picking your vegetables

We just completed filming for Harvests, a look at autumn’s abundance and how to deal with it, so there are many tips on timing and methods of picking, for best quality results and continuing abundance of some plants you are harvesting from. The film is in three parts – Salads, Autumn vegetables and Winter vegetables – and will be up on YouTube by month’s end.

The photos show one or two stills from the film, including beans for drying which is an ongoing harvest for the next month, and with bountiful crops here of both Borlottis and runner beans.

Last of the summer fruits

Its time to prepare the end of summer-fruiting plants. There should be no flower trusses or tiny tomatoes, only ripening and medium-sized green ones, so they all ripen by early October. Reduce watering a little and keep leaves on above the lowest truss with fruit on – if you remove all leaves, the flavour and fruit quality is lower.

Basil tends to lose quality when nights are cooler, and all summer plants suddenly grow less after the equinox. It is frustrating sometimes if you have been waiting for aubergines to grow or peppers to ripen but if you want to plant winter salads and vegetables undercover (see below), sometimes you have to cut losses and remove any under performing summer plants.

Last October I dug out roots of Stevia to keep alive in pots in the conservatory and you can do the same with chillies: then repot or plant them again in April undercover, or late May outside.

The melon plant below is growing up a string in the polytunnel, its fruits are unsupported and weigh nearly 2kg each.

Salads undercover

Its a good time now for sowing almost any kind of salads for undercover cropping through winter. By 20th I rekon to have module-sown salad rocket, mustards including Red Frill, Pizzo and Green in the Snow, spinach Medania, winter purslane (claytonia), leaf radish and tatsoi. No pak choi because of slugs. Lettuce and endive were sown a week ago, chervil and coriander are small seedlings already too.

All are for planting by mid October after clearing tomatoes, basil, aubergine etc. There should be no need to spread any compost unless you put only a little on in May. Here I spread 2-3inches compost in May and then no feeds or anything else for a whole year of intensive cropping.

Salads outdoors

For outdoor salads, you could still sow mizuna, mustards and salad rocket, because they establish and grow so fast. But yields will be small in autumn and winter, compared with if you had sown in late August. Covering with a cloche or fleece is worthwhile: cloche gives better protection but needs watering by February and onwards, while fleece needs little extra work as long as it is not damaged by wind.

Amazing open day, posted September 1st

We were blessed with a day of sunshine and soft breeze on August 31st, encouraging so many people to come and see the garden, around 250 I think. Also they enjoyed eating a great range of cakes made by Steph, of which the parsnip cake was most popular.
Thanks to all who came along for your contributions to Send a Cow, I have sent them £308, enough to buy some bees, fruit trees, seeds and much else.
It was good to chat with lots of you on the day and to hear of your own experineces growing great food.

Late summer, early autumn weather

Now the weather is settling down and it looks a mostly fine September to come, and warmer. Though even with warm days, from mid month the nights will cool down and a ground frost is probable in rural areas (not in towns) any time from about 15th.

Looking back, the middle of August was unseasonably windy and turned cold for a while, such that we only just escaped a frost on four nights from August 21st-24th, a remarkable thing in summer, completely outside of my previous experience. If you had a frost, it will have caused lots of damage. It was the coolest August since 1985, here, although it was as sunny as July and the good light levels helped growth.

August 2013 2014
Max Temp C (F) 22.2 (72) 20.0 (28)
Min Temp C (F) 12.4 (54.3) 10.2 (50.4)
Rain mm (in.) 47.5 (1.9) 110.1 (4.4)
Sunshine hrs 180 180

Watering protected crops

Summer stalwarts are in their final phase of maturing fruits before growth really slows in October. Keep pinching all new shoots off tomatoes and water as little as you dare, to encourage plants into ripening rather than growing. For plants in soil, don’t worry if the surface looks mostly dry: check with a trowel if in doubt, to see what moisture is underneath. However in the first fortnight of September when sunshine is more warm and abundant, tomatoes still need a fair amount of water to sell new fruits.

Cucumbers are still fairly thirsty, as are aubergine, pepper and chilli if still full of leaf and fruit. Melons should be in a final phase of ripening and can be left on the dry side. Leafy plants like basil need careful watering to avoid too much on their leaves, which otherwise can discolour in the dampness of autumn.

Sowings for winter salads undercover

This month is the key time!! If doing a few, I would sow everything just before mid month, to save time. You can sow into modules, then plant after three to four weeks as space becomes available after summer vegetables finish. There is a full moon on 9th September, so the weekend of 6th/7th looks good for rapid germination and strong growth.

Here I split my sowings because of growing a larger amount of salads. I sow slower growing seeds like land cress and wild rocket now or even in late August, then lettuce Grenoble Red  and Winter Gem (hardy Little Gem for leaf picking), endives, chards, spinach Medania and winter purslane by mid month, then the faster mustards, salad rocket and leaf radish by 20th or even 25th.  All with the aim of planting through October as space becomes available after clearing summer vegetables, and giving the soil a thorough watering.

Weeds and preparing ground for winter

This topic has been live on the forum and there are questions about green manure. Now is best time for sowing white mustard (Synapsis alba) which grows fast and thick to add organic matter after it dies in frost, through its roots in the soil and decaying leaves on the surface. A few plants may survive if winter is mild and I needed to pull some out this February.
Mustard keeps weeds down but I recommend pulling any weeds you see to prevent any of them seeding, After green manures die off there is usually a residue of slugs in late winter/early spring, more than if you spread compost in autumn and leave soil clear of growth, just with the compost on top as a mulch. This keeps worms busy underneath, helping more air to enter through their tunneling, and soil is then ready for spring sowing and planting without any need for loosening by us.

I see the main priorities as:

  • soil food, be it green manure or mulch
  • minimal weed growth so that none set seed – for example bittercress, cleavers, annual meadow grass and chickweed all set seeds in winter.

September harvests

No rush to harvest winter squash, even if they are well coloured. Wait until the stalks are dry and brown, but if you need to harvest before that, make sure to keep them dry and warm (25C) for a fortnight after picking, to finish the drying process and give good storage potential.

No other harvests for winter are happening yet, because September is a good month for root vegetables such as celeriac to increase in size, for cabbage hearts to swell, and for beans such as Czar, borlotti and heritage varieties to finish swelling and then dry, or mostly dry, on the plants.


Watch for damage by the larger, summer slugs which have become abundant after August’s rains. Most come out as soon as dew falls in the evening and you can make a worthwhile difference with a knife by torchlight. I find they really motor along at dusk, heading for delicious salads, brassicas, french beans and new plantings above all, so it feels ok to cut them, to me. If you lose plants to slugs, you then have to buy them, often grown in a more nature-harming way.

Leaving a stone or plank of wood on the edge of your garden offers refuge to slugs by day, when you can cut or catch them to reduce damage. The larger brown and black ones can eat a lot of leaves at this time of year, building up their reserves ahead of winter. Do be especially vigilant after planting any new seedlings.