Grow Organic Food » Square foot gardening

A difficult gardening year

Colin — Wed, 07 Sep 2011 08:03:45 +0000

The weather has made this a difficult year for gardeners. The prolonged drought and cool summer caused stress to many plants and reduced yields. As usual there are winners and losers.

We cut back the number of potatoes planted this year from two 15ft x 4ft (4.6m x 1.2m) to just one bed because last year we the harvest from the two beds was ~ 200lbs (91kgs) which was far too many. This year we had 130lbs (59kg) from one bed. The bed was planted with 19 tubers, the variety is Sarpo Mira which we really like. The ~30% increase in yield was unexpected.

Some crops failed while others just did not do well. Dwarf French beans did not germinate while the carrots in one bed germinated but suffered continual attacks from voles who undermined the roots and generally disturbed the seedlings. Now they are eating the carrots!

Tender crops like sweetcorn suffered a double whammy by not liking the lower temperatures and suffering from the drought. We have watered them but obviously not enough.

The major disappointment of the season is onion white rot in two beds. It affected about half the main crop onions and some of the square metre bed crop.

Overall a difficult year with the usual successes and failures that makes gardening so ‘interesting’!

Is spring is just round the corner?

Colin — Wed, 02 Feb 2011 07:56:07 +0000

With the days getting longer and the constant reminders that it is time to start sowing seeds anybody would think that spring has arrived. There are endless articles in magazines about what to grow this year and last weekend one garden writer said it was time to sow tomato seeds. While this is perfectly possible if you have a heated propagator in a heated greenhouse and extra lighting I would suggest that it is far too early as you will need heat and light for 2-3 months and that it both expensive and unsustainable.

Here in the ‘frozen north’ we do not plant out tomatoes and other of more delicate plants like courgettes, squash, dwarf French beans and sweetcorn until early May. So if you sowed the seeds now that would mean holding them in pots in a warm, light place for three months which is not good for the plants or you bank balence

Sowing seeds outside in February is also daft. The winter has been hard and the last time I looked at the soil it was frozen to a depth of maybe 2-3 inches ( 10-15cms). Obviously most seeds will not germinate at those sorts of temperatures yet we are constantly told that February is the month to sow parsnips. Many gardeners complain that parsnips are difficult to grow and, you guessed it, when asked they say they sow in February. I cannot understand why the seed companies and garden journalists recommend such early sowings.

The best way to sow at the right time is to know your own plot. Some gardens are colder than others and after a few seasons you will come to know what works for you. Take into account variations in the weather as after a very cold spell it will take a while for the ground to warm up.

The second tip is to measure the soil temperature and then find the minimum germination temp for the seeds you want to sow. See our germination temperature chart here.

My last tip is to be patient. We all want to start sowing seeds but if you get carried away and start too early there will be failures. Wait until conditions are right and you will have good crops of strong healthy plants.

Comfrey juice fertliser

Colin — Mon, 28 Jun 2010 06:32:51 +0000

There seem to be some misunderstanding, and not a little controversy, about how to make and use comfrey liquid fertiliser. A recent article in the Sunday press by a well known gardener stated that making comfrey tea was an easier option because it did not need to be diluted.

In his book “Comfrey past present and future” Lawrence Hills is quite clear about making comfrey juice i.e. concentrate not tea. He spent many years studying comfrey and even had a chemical analysis that showed comfrey concentrate had virtually the same constituency as Tomerite, see this page.

I am all for making things easier for newcomers to organic gardening but sometimes gardening celebs go too far. Comfrey tea is a very different thing to comfrey juice and will not have the same effects on plants. All too often I was asked why plants were not thriving and the usual answer was that they were not being fed enough, sometimes not at all!

Comfrey is an amazing plant and 0ne that every organic gardener should grow. Making comfrey juice is a good way to get lots of free fertiliser, just remember to dilute 1:10 for tomatoes (that’s 1 part juice to 10 parts water) and 1:20 (that’s 1 part juice to 20 parts water) for everything else.

More late frosts

Colin — Sun, 09 May 2010 07:04:42 +0000

There are yet more frosts forecast for us this week. Some forecasters are saying the temperature could go as low as -4C! Cover anything that is tender especially exposed potato tops or they will be damaged and wait for summer. The cold weather is retarding out asparagus crop which did suffer damage last week. Shame.

So is it spring yet?

Colin — Tue, 02 Mar 2010 17:02:31 +0000

There has been much debate on TV and elsewhere as to the ‘official’ start of spring. Some say its March 1st while others argue its March 21st. It’s all a bit academic as the soil here is too cold for sowing seed and there are still sharp frosts at night.

Gardeners should know their own gardens and be able to tell when it’s time to start sowing seeds or planting out. A useful guide is the soil temperature and this chart gives an indication of the minimum temp for germination of common veg seeds.

What often irritates me at this time of the year is the advice from gardening experts who say things like its time to plant your potatoes in the middle of February. That would have been impossible here as the garden was under several inches of snow.

There are all sorts of myths about the correct time to sow but the only real indication is the soil temp, the weather and the state of the soil. Rushing to get going on the first warm day will most likely result is failure. Wait until conditions are right and your plants will grow strongly and give a good yield.

Tomatoes can ‘eat’ insects

Colin — Tue, 08 Dec 2009 09:11:06 +0000

There is nothing like a sensational headline to attract attention. According to a recent article in The Telegraph tomtaoes are amongst a group of plants that trap insects, kill them and let their bodies fall to the ground where they decompose and add to soil nutrients. That is clever but not quite like eating them.

The article continues the hype by saying

The study said it is likely that the meat-eating qualities of many plants has gone unrecognised because they are missing some of the prime characteristics associated with carnivorous species.

There is a big argument that says they are not really eating meat but are composting the bodies and then absorbing the nutrients but there again that is not really a headline grabber.

What this research does show is that we still have a lot to learn about plants and the delicate web of life on this planet.

How to grow 100lbs of potatoes in 4 square feet

Colin — Sat, 21 Nov 2009 09:49:19 +0000

This idea has been around for some time and while there are many ways to grow potatoes in containers this system has some advantages. The first is that it is set on soil so the tubers can root as deeply as they want. Second, by using a wooden box with removable sides it is easier to harvest the spuds at the bottom of the pile.

I must admit to be sceptical about the claimed 100lbs (45kg) from 4 sq.ft. (0.36 sq.m.) Using good soil beds we get around the same yield from 60 sq.ft. (5.5sq.m.) so a 15 times increase would suggest a lot of extra inputs in terms of fertiliser and water. Careful management would be the key to getting such good results.

Most posts suggest using a base frame with four uprights used to attach the sides. Remember not to use any sort of treated timber for the box in contact with soil.

The photograph shows 9 halves of seed potatoes (whole tubers cut in half) in one square foot. Even with good fertilisation and lots of water that seems like very close spacing. Potatoes are hungry feeders and very thirsty plants and maybe this is over optimistic?

From my experience last year with potatoes planted in a dustbin (trashcan) I would use 3-5 seed tubers for a variety known to be good for container growing e.g. Charlotte and maybe 2 tubers for my favourite Sarpo Mira.

I plan on making this one of our 2010 trials to see just what yield we can get from such a small space.

Here are detailed instructions of how to make the box.

Square metre bed trial – update

Colin — Thu, 01 Oct 2009 06:55:52 +0000

I updated the results from the square metre bed trials yesterday, click here. While the amount of food produced from such small beds is impressive I think greater yields are possible.

The soil in this part of the garden is still very heavy clay which has not had the amount of organic matter it really needs. Also, the beds received a single application of organic fertiliser and better results may be possible by smaller applications throughout the growing season.

Having said that I am still amazed at the productivity; to get 35.40 kg or 77.80 pounds of food from just 4, 1m square beds seems incredible and will certainly change the way I manage the rest of the garden.

Asking for help

Colin — Tue, 22 Sep 2009 08:45:14 +0000

Since the new site was launched earlier this year the number of visitors has increased dramatically reflecting the huge interest in growing food. This is good to see and provides encouragement to carry on.

There are many plans for the coming months including an electronic newsletter, more garden trials and a series of short ‘how to do it’ videos.

This all costs mone. Unlike similar sites I have never thought of sectioning off content for subscribers or asking people to pay for what they view as I believe content should be free.

The ISP fees are just under £100 a year. This includes domain name registration and a high bandwidth account to cater for the very large number of hits we get each year. It costs about the same for renewable electricity to run the admin PC . We get no grants and no income from any source, other than a very small amount from Amazon, so your support is crucial.

PLEASE make a donation using PayPal, you do not need an account and it is as secure as any other online payment but if you still not happy email me at admin@organicgarden.org.uk

Single crops in 1m square beds – the harvest continues

Colin — Mon, 07 Sep 2009 05:58:48 +0000

I have now dried and stored the onions from the square metre bed. The end result was 68 onions weighing 8.6 kg (18.92 pounds.) Last year I predicted that it would be possible to get 10 kg (22 pounds) of onions from a single square metre bed and the results show it is possible.

Both the carrots and runner beans (pole beans) are still producing well with impressive harvests.

The onion bed has been sown with Claytonia (Corn Salad or Miner’s lettuce) in 9 stations. The lettuce bed has 9 Hispi pointed cabbage plants that are doing well.

Overall impressive results which proves that a significant amounts of food can be grown in such a small area.

See these pages for more details of the trial: Single crops in 1m square beds, Single crops in 1m square beds – first results