March 2015 sowing, propagating, mulching

March 2015 sowing, propagating, mulching

Sowing, spinach, potting composts, providing warmth with a hotbed, dishes of winter vegetables, mulching allotments,  Homeacres compost loo

Be weather-wise in March and if it stays wintry, don’t rush to sow. Months often follow a pattern of similar weather, for example in March 2013 the average temperature by day was only 8C and with twenty nights of frost, then last year it was a balmy 12.5C by day and there were only three frosts.

Usually the weather is between these two extremes, and has warmed up enough by the March equinox (21st), a good average time to sow carrots, parsnips, salads, spring onions, radish, early potatoes, onion sets and spinach. For sets of red onions, sow in April so that they suffer less cold weather, which is what triggers them to flower.


Spinach may confuse you because the same word is used to describe different vegetables: I recommend sowing true spinach (Spinacia oleracea) in March, but wait until April to sow leaf beet spinach and chard (Beta vulgaris) as they are more inclined to bolt when sown too early. In fact I sow leaf beet in April and chard in May, to harvest leaves all summer and autumn.

True spinach is the other way around, because it flowers quickly if sown in late April or May – whereas March sowings give more leaves before its flowering period in June. You can sow it undercover in modules now, to transplant in early April, and cover the bed with fleece as protection from birds, rabbits and to speed its growth. Fleece laid on plants creates a greenhouse effect below. Through May the leaves of true spinach are a treat both cooked and in salads, with less of the bitterness found in leaf beet and chard, although that is reduced by longer cooking. All the photos are of true spinach, showing how I cover early plantings with fleece directly on top, to conserve extra warmth, and save time (no hoops).


Potting composts 

The offer is always changing and now Viridor have produced a multipurpose compost, based on recycled green waste and without any peat. They say its not designed for sowing into, even though it is called multipurpose, but I did a trial and found that cress germinated and grew better in it than in my West Riding multipurpose. Possibly the cress in Viridor’s compost is helped by the large amount of wood which improves drainage, but its too early to be sure.

For potting on I wonder if all this wood will grab some nutrients for its own decomposition, we shall see. I used the tray of a wormery (5mm holes) to sieve out the wood and then sowed radish in both sieved and unsieved versions, as well as in West Riding. Watch this space.

One thing I now think is that the West Riding compost is a little rich and/or dense for seeds of lettuce, spinach and beetroot. But cabbage, dill and coriander have come up fine.


Warmth is most valuable for germination

There are two phases to the early growth of seedlings: germination and subsequent growth – and they need different conditions. Germination requires extra 24 hour warmth because seeds are wanting to be sure it really is their time. Airing cupboards and boiler rooms are excellent for germinating seeds, just remember to retrieve them before they grow long stems in the darkness.

When conditions are too cold, seeds cannot germinate and risk rotting, although often they are just waiting. Look at how tomato seeds survive in sewage and then germinate in spring warmth.

At Homeacres I am using a hotbed in the greenhouse, for germination and early growth of seedlings. Within 48 hours of filling the bed with fresh horse manure and straw bedding, the temperature a foot (30cm) into the heap had risen to 75C, and there were plenty of steamy vapours rising all the time, more than I had when the bedding included wood shavings. This did not affect the seedlings but my salad plants were slightly damaged on their leaf ends, developing white blotches; it looks like I needed to ventilate more during that first week. Now the temperature is below 60C and the steaming has stopped. 

The core temperature stays above 40C for around six weeks, in a heap of this size – less for smaller heaps. You can boost the temperature, say in early April, by removing plants to add more fresh manure on top, that is good for sowings of squash, courgette, cucumber, basil.


Eating winter vegetables

Steph has created some super salads for course lunches. My favourite in February was borlotti beans, chopped salad leaves and (pre-soaked, then oiled) dehydrated tomatoes, red onion, garlic all grown at Homeacres, and dressed with balsamic vinegar with olive oil. Although a “salad”, this could be a main course too. Steph has also been experimenting with preparation of yacon and oca, and her recipes will be in the May issue of permaculture magazine.



Allotments, starting out

The photos below are from 2009 when Steph converted her allotment to no dig. She had been reasonably on top of weeds and did a final clearance in February before we spread 3-4in (7-10cm) of green waste compost over the beds and paths. It cost £80 for 4 tonnes. Other allotmenteers commented that the compost “needed incorporating” but leaving it on top meant she needed to do very little weeding for a whole year, until the compost was taken in by worms, and crops were impressive. Then the following spring she spread just an inch (3cm) of cow manure on the beds, which cost £10.

If you have lots of weeds before starting no dig, you can either use a slightly thicker layer of compost, as a one-off application to kill weeds, or less compost with polythene or cardboard on top. The latter is worthwhile mainly if there are perennial weeds such as couch grass. See my archived posts from January 2013, which take you through my methods of cleaning weedy soil here at Homeacres.


Compost loo

After much carpentry by the two Dave’s (see February post) and a wwoofer Neil, Homeacres loo is now working. I am impressed with its potential. Outside I have planted willow cuttings of various colours to make a hedge around the road side. After mulching the grass with cardboard and landscape fabric, I used a crowbar to make foot-deep holes for the willow stems.


Warmth demanding vegetables

Its time to sow some frost-sensitive vegetables which need steady warmth to grow, say above 10C by night and 20C by day, more if possible. For March sowing they are are tomato, aubergine, sweet pepper and chilli. Sow them now if you can keep them warm.

Another and possibly cheaper option, if you need only a few plants, is to buy them as plug seedlings in April. I do this with Black Pearl aubergines, my favourite for remarkable harvests. Grafted plugs are even more abundant and cost £1.90 each from I have seen no benefits from grafting of other vegetables, only aubergines have been worthwhile for me.

Two other groups of heat-loving vegetables are the cucurbits – cucumber, melon, courgette, squash – and summer beans, both French and runner. They want sowing later, around mid April for cucurbits and mid May for beans. Make sure you have their seeds but keep them dry for now.


3 thoughts on “March 2015 sowing, propagating, mulching

  1. How effective is spent hops used as a manure and will it stunt growth or damage other plants etc. Cannot find much info. on web sites generally.

  2. Charles
    After visiting you , in March last year, we put up a hot bed in the poly tunnel and we filled it with fresh (1 day old!!) horse manure with straw and a bit of shredded paper. We first did this on 28th December and it then sunk about a third, so we then got another load of fresh manure and replenished the hot bed, like you, the temperature went up to about 6oc. and that is the maximum on the soil thermometer!!!!. On the top of all that we have put a polycarbonate sheet that we were given when a neigbour was clearing out his garage, and the maximum temperature under that is 50 c I hope I have not cooked the seeds. Thanks for the inspiration it works so well. Ali

    1. Thanks for posting this Ali its great to hear. Mine has sunk a lot too, I shall replace it all in three or four weeks, with another batch of fresh manure. Topping up is good too.

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