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March 2021 new no dig gardens, starting seeds, potting composts and trays

Written by

Charles Dowding

Last Updated

February 28, 2021

This is a full on time for a propagation, although also there is no rush to sow tomatoes, cucumbers, courgettes, sweetcorn et cetera. Spring is also good for making new beds, which you can actually do at any time of year. See all the details below!

My new online course 3A has appeared. Seed to Harvest, the First 15 of 30 different vegetables.

Each lesson is one vegetable, in a lot of detail and with a video.
I have just finished writing 3B the Second 15 and we are editing it, prior to publishing before the end of March.

Normally it’s reckoned that March comes in like a lion and goes out like a lamb. However this year maybe it’s the other way round, with March starting quietly. After a windy and dull February, just 63hrs sunshine in the month, see my weather details.

Outdoor salad plants corn salad, winter purslane — Outdoor plants of Claytonia and lambs lettuce or corn salad which we transplanted four months ago in late October

Loading manure for a hotbed — The last wheelbarrow load of fresh horse manure for my new hotbed. Most of the manure goes in through the tailgate, but by this stage the trailer is very full

Transplanting wild rocket in a no dig but — Transplanting wild (not salad!) rocket with Martin, the first planting of 2021 and these plants have been in the greenhouse since September, even we have picked them twice for a salad leaves!

Starting seeds

Don’t be overawed by what you may read on social media about people starting their cucumbers and even summer beans. They have their time for sowing, and it’s not yet! See my timeline of sowing dates, and Calendar + Diary.

Multisowing is catching on now. It’s such a fine way to save space and compost, and seedlings enjoy being in clumps with their mates. See my guide for which vegetables work best, and how many seeds to sow per cell. This page is available in Spanish and Italian too.

Multisown spinach seeds on 15th February, with 2 to 3 Seeds per cell

Multisown onion seeds 15th February, average five seeds per cell. With multisowing I water after the seeds are in

Germinating seeds in the conservatory — After sowing I bring all the trays into my conservatory, because the night temperatures are much higher in there compared to the greenhouse. Once I see the first leaves, the trays go back outside

Seed germination

The first few days is all about warmth. Seeds need higher temperatures to germinate than the seedlings need to continue growing. That’s why I bring trays into the house for the first few days, until the first shoots appear.

At this point it’s important to give them full light, to prevent thin leggy seedlings. Either with grow lights in your house, or outside where either it is cooler, but perhaps you can provide some warmth. I have space for a hotbed of fresh horse manure with straw. Electric mats are good too. See my propagation video.

In temperate climates you can also manage without extra heat at the moment, because all of these first swings are not tender to frost. You can also germinate seeds of lettuce, spinach, salad onion et cetera in a propagating area outside, but germination will take longer.

module trays sown and germinated — Module trays sown and germinated or germinating, on the hotbed 26th February

Temperature difference from using a hotbed — The top temperature is of air in the greenhouse at dawn, and the bottom temperature is from a probe which is sitting on top of the hotbed, just underneath the trays.

Propagation, more seedlings are appearing — Just one day later and more seedlings are appearing, it can be nerve wracking to wonder at this point, are they all going to appear. There is spinach, onions, radish, turnip

Which compost for potting?

Composts vary so much and over the years I have found Moorland gold to be the most consistent. However they tweak the recipe every winter, and so every spring I have nervous moments of wondering is it working this year? This spring at first some of the ingredients went a little mouldy and also the density felt too fine, resulting in a shortage of air for the roots, see the photo below. Therefore this is not good for sowing seeds in a tray, but it works very well in modules for sowing. In a tray, you can add 50% or more of vermiculite or perlite.

Which? Gardening ran a trial last spring on different composts and found that one of the worst for sowing seeds was John Innes No. 1. A reader sent me the photo below of his problems with it, and there are some poor compost being sold! Better ones include the Melcourt range, possibly Dalefoot if they have worked out their nutrient issues since last spring, and I usually hear good reports about B&Q compost.

My trial of composts for growing peas — Moorland Gold potting compost on the left in this tray which is lined with two sheets of newspaper, and my home-made compost on right, sown with peas for shoots

Homeacres compost after I sieve it — Homeacres compost after I have passed it through a 12 mm/Half inch sieve, and the bits you see are good for drainage in propagating. However the nutrient status is lower compared to Moorland Gold

Poor germination in John Innes sowing compost — Poor germination in John Innes No. 1 sowing compost on left, compared to Dalefoot on right, thanks to David Meaker

Trays? Blocks?

I am enjoying using the trays which I designed, for the first time. The only seeds I would not use them for are broad beans, and perhaps multisown pea, although I am trialling that.

I use larger trays for broad beans, but they are not deep. A 5 cm/2 inch depth is plenty, despite what you may read about broad beans needing deep trays for their taproot. My online course module about propagation has these details.

I use trays rather than blocks because I have found it takes quite a time to make the blocking mix, and then you need dedicated trays to put all the blocks on. I cannot find a blocker for the size I want, either they are smaller or larger. With the CD 60 I can fit a lot of cells in a small area. Plus the trays can be reused time and time again, always without any cleaning or washing, so it’s a rapid process.

Comparing module trays empty, my CD60 left and a less solid, once used Erin 60 right

Before sowing or pricking out, I push compost in firmly and fill trays to above the level of the cell divisions, because the compost always sinks once it is watered. Each 60 celll tray used exactly 2 L of compost

old 40 cell trays sown with broad beans — These old polystyrene 40 cell trays are sown with broad beans which I germinated three weeks ago on the mantelpiece above my woodburner

New ground, mulching weeds no dig

We grab any spare moments to do more mulching of the grass and weeds. No dig can be a nice incremental process where you chip away at a larger space, bed by bed. Learn more in the book of my online no dig course – what you see here relates to module 4, about dealing with weeds without digging.

The size of this new area (just 260 sqm / one fifteenth acre) has led me to use polythene covers for the first three months or so. Under the polythene are various combinations of some spare topsoil I had, cardboard and compost. The latter is mostly green waste and I have done a bean trial to check that it is free of weedkiller. The bean seedlings are actually growing extremely well!

To save time I am not shaping beds and paths at the moment, just covering the whole area. We shall eventually do a final dressing of some extra compost on what will then become beds, and without any wooden sides.

Sheets of plastic keep it dark on weeds — Sheets of plastic keep it dark on top of grass and weeds trying to grow underneath, where we apply some soil, card and compost

Grass regrowing after three weeks under polythene with a little soil on top. Now we are placing cardboard on top and then there will be compost on top of that

Cardboard

Until two days ago I did not have enough and mentioned this on a YouTube members video, and a gentleman Steve appeared with a pallet load of cardboard, fit was used for plumbing appliances. Nice cardboard but a lot of staples.

In the photos below, the area in front has only soil on the pasture weeds, without any cardboard underneath. So now we shall apply the cardboard on top of the soil already spread, then the compost above that. I should have preferred to lay cardboard first, but things don’t always work out to plan.

Mulching one section in the middle with cardboard on the grass and weeds, Kate and Martin, a good job on a cold morning

Green waste compost which Kate is raking more or less level — I am using some soil because I happen to have it! One could use only compost and this is green waste compost which Kate is raking more or less level, not perfect at this stage, about 10 cm 4 inch depth of soil plus compost

After adding these mulches we replaced the polythene and it will stay like this for at least six weeks maybe longer, I am still unsure exactly what will grow here

Perspective

The drone shot gives a nice idea of how small the new area is! Although it seems quite large when we are working on it.

26th February drone view over Homeacres shows how we are mulching only a small area of the new acre

The newly covered area will eventually look like this and is twice the size of what you see here. In front is the wild rocket we planted this week.

Bed prep existing no dig beds

This video we made 11 months ago gives ideas of what jobs you can do over the next month. One is to watch for new weed seedlings and deal with them when they are tiny, because that is much quicker and easier than letting them grow to any size at all.

It took me no more than 10 minutes to run a rake through the beds below, in the photographs. It’s a big advantage of having spread compost just before winter. The frosts have softened it and now it has a beautiful texture, ideal for receiving seeds and plants.

No-Dig is just such a win win
It saves time, saves effort, drainage has been excellent over winter, and moisture retention is excellent through summer.

Mulch of home-made compost after taking the final harvest — These beds had beetroot and chicory until last December, then we spread home-made compost after taking the final harvest. I am now passing the rake very lightly through this compost, I have started on the right hand side

Lightly raked to disturb tiny weed seedlings — After raking the surface at no more than 3 cm / 1in depth to break lumps, level the surface, and disturb any germinating weed seeds. The paths have a 2-3cm cover of wood chip, and no cardboard or membrane. We pull any new weeds in the paths, there are few.

New weed seedlings — This is the size of weed seedlings which you want to be either pulling, or hoeing, or passing a rake through. Catch them small.

New garden Netherlands

The photos below were sent by Gerrit from Friesland. He has created a lovely growing space! I love how no dig is spreading to so many places.

In a week or so we shall release a video we are creating with Wini Walbaum in Santiago. You will see our different gardens, in different seasons, and the conversation I have with Wini, who has not been gardening for long but is very happy with results of no dig, especially for moisture retention.