April V: doubling the spring radish harvesting season…

Radish is a wonderfully useful little crop to grow in spring, as it will finish harvest by the first week of June, meaning it can be sown and harvested prior to sowing/planting out maincrop beetroot, maincrop carrot, leeks, dwarf beans etc.

Here in NW London, I have found that sowing radish direct before the end of March gives poor yields, so the earliest realistic harvest date for directly sown radish is around May 5-8th.

As I also find that the warmer temperatures see pests eating young radishes, the latest I tend to sow radish direct in spring is around April 20th, giving harvests up to around 8th June.

So, simply sowing outside limits the harvest to about four weeks.

So over the past two years, I have experimented with sowing radish in modules indoors with 160 radish seeds per 40 module tray. With rapid germination, this year I sowed modules on 25th February and transplanted the speedy half on 6th March and the slower growers on 13th March.

I sowed a second batch on 23rd March and transplanted them all on 31st March.

By doing this, I had six rows of 12 modules in a 1*1.5m area.

The aim is to harvest 12 roots a day for 20 days from April 20th, freeing the first five rows by May 7th to allow sowing of four rows of carrot maincrop.

The remainder of the radish season will then come from directly sown rows.

To harvest 12 roots a day (four each for three people) for fifty days means 600 harvested roots. With a sowing density of 200 roots per square metre and 1000 seeds sown, that implies 5 square metres of soil to cover the crop. Whilst this is 10% of my garden, I plant 12 square metres after the end of May with beans and leeks, whilst maincrop beetroot and carrot can follow earlier sowings and parsnip and carrot sown in April can be interplanted with radish too.

A nice way to add healthy bites to the salad bowl in spring.

March 2017 VII: My 2017 potato plan….

WIth the spring equinox having passed yesterday, thoughts turn toward planting the potato crop in my 7.5 sqm bed.

Having experimented a bit over the past 5 years, I have now settled on a formula that seems to work OK.

It goes something like this:

1. Ultra early potatoes are planted in pots with airholes at the bottom. The feature image shows my 2017 Foremost 1st early plants having just broken through, with a crop planned for June. They live indoors from planting in late February until now, when they will live outdoors. The target yield is 5-8lb from four 15 litre pots.

2. 3 rows of 6 first early tubers positioned 10cm, 35cm and 60cm from the end of the bed. The aim is a harvest of 20lb in total, for harvesting in late June and July. I am growing one row of Foremost and two rows of Dunluce.

Pentland Javelin and Arran Pilot have both proven reliable in the past.

3. 4 rows of 5 second early tubers positioned in a 30cm equilateral triangle lattice with the rows at 85cm, 110cm, 135cm and 160cm from the end of the bed. This year I am growing Kestrel, in the past Charlotte and Estima have both worked well. I harvest these around 31st July for eating in August and September. The target yield is 40lbs from 20 tubers.

4. 8 rows of four maincrop tubers positioned at 200cm, 240cm, 280cm, 320cm, 360cm, 400cm, 440cm and 480cm from the end of the bed. I have settled on 4 rows of Desiree (which tolerate dry SE England summers well) and 4 rows of Sarpo Mira, which are blight resistant. The target yield is 100lb from 32 tubers.

5. 8 bags of exhibition potatoes planted elsewhere. This year I am just sowing Kestrel, in previous years I have also grown Casablanca. The target is for quality potatoes, not yield, but usually 16-20lb of tubers emerge from the bags.

I have tried growing maincrop potatoes in 35 litre pots, as achieved superbly by Dan of www.allotment-diary.co.uk fame, however I wonder if the temperature within pots in the SE sometimes gets too hot for optimal tuber production? Dan gardens at 1000ft above sea level in the Yorkshire Dales, so it may be that what works in a cooler area does not always transpose to a hotter one? I have achieved 9lb in one pot in the past, so it is certainly possible down here. Daily watering is often necessary for success….

This year, I will plant all my potatoes, except those in pots and those for exhibition, on 9th April. This is two days before full moon, a root day (ideal for potatoes) and a descending moon. Everything a planting day is supposed to be.

Let us see whether such a perfect planting date will yield the 160lb of potatoes I am hoping for….

Exhibition potatoes will be planted on 29th April or May 6th, depending on how long I dare keep the seed potatoes in the shed.


March 2017 VI: My 2017 tomato plan

Today, March 10th, is my main day for sowing tomatoes. So a post about my seasonal plan and how it generally works out.

First, let me say that I grow tomatoes in pots as I have neither a greenhouse nor a polytunnel. The plants live under a carport when it rains in summer, and follow the sun around the front and back gardens when it is fine. Oh, for a slave to do all the moving for me!

I plan my season in three groups:

1. Two cherry strains sown in February to provide tomatoes in June and July. They are grown for earliness, not yield. The first harvest depends how warm May is as a month, rather than how early seeds are sown (I base sowing around the February full moon): my earliest harvest is June 9th. Late June is not uncommon as the first harvest date. I grow Maskotka and Red Alert as they are not fussy, tolerate cool weather and are reliable croppers. Red Alert harvest usually ends by 31st July.

Here are my 8cm tall, 8 cm wingspan seedlings 26 days after sowing:

2. My March sowings cover Beefsteak varieties, plum varieties, salad tomatoes and cherries. I sow Super Marmande, Black Russian and Black Krim as they seem to crop reliably outdoors as beefsteaks; I am experimenting with San Marzano as a plum variety; I grow Alicante and Tigerella as reliable salad strains; and I grow Black Cherry as a reliable cherry variety, which will often crop well into autumn. My first maincrop harvest is usually around 21st July.

3. My April sowings are for competition, using a Quadgrow to produce a few trusses of high quality tomatoes. I grow Sungold as a cherry and Zenith as a salad tomato.

My usual yields are:

Beefsteaks: 8-10lb/plant;

Salad Tomatoes: 5-8lb/plant;

Cherry Tomatoes: 2-6lb/plant.

I aim to harvest 100-150lb of tomatoes, depending on season, summer heat etc.


My failsafe germination method is as follows:

1. Take an ice cream tub and fill two thirds full with John Innes seed compost. Saturate this with water.

2. Add 1cm of further seed compost on top.

3. Lay seeds in rows on top of the dry compost, then cover with a sprinkle of seed compost.

4. Cover the tub with aluminium foil, place on the warm surface of outside boiler and leave to germinate.

5. From day 3, check daily for germination and bring indoors as soon as plants emerge (usually day 4-6 using home made seeds).

The method aims to mimic Mediterranean soil with a dry surface covering wet subsoil being warmed by strong sunshine.

Obviously, heat sources depend on what you have available. Electric propagators and airing cupboards also work well.


March 2017 V: growing large onion bulbs from seed

Early March is about the latest time to sow onion seeds if you want large bulbs come August. I have successfully grown onions by direct seeding in the ground in mid April, but that is really mostly going to create smaller bulbs for pickling or cooking soon after harvest.

Onion growth can be split into three real phases:

1. Germination

2. Growth of foliage up to the summer Solstice

3. Bulb development until foliage collapses in mid to late summer, when harvesting takes place.

Germination of seed is a bit of an art form, particularly early in the year (prior to mid February) when conditions are not promoting natural germination. Some suggest that the best natural conditions are soil temperature of 13-14C, with nights down to 10C (with germination occurring in 10-14 days), whereas I have often found better germination with a pulse of higher heat for two or three days, which can be delivered a week after sowing seeds in trays or modules. Ultimately, you have to try things out yourselves.

For the largest bulbs, transplanting seedlings at the ‘hook’ stage (2-3 weeks after sowing) is recommended. I do this into 8cm pots, transplanting 40 seedlings intending to plant out 35. For about a month, this means that onion seedlings may dominate your sunny windowsills, which is why I sow my Kelsae onions in early February and my main batch of tomatoes in mid March. This means that the windowsills become available for tomato seedlings just as onion plants can be moved elsewhere. It all depends how much indoor space you have.

Once seedlings have been transplanted, daily foliar water sprays benefit indoor plants, as will a weekly foliar feed with a dilute liquid seaweed. Watering from underneath (I use 600ml once a week for a dozen 8cm pots in a 40cm tray) is the way to ensure uniform moisture without flooding.

4 weeks after sowing, >90% of seedlings should have a well developed first true leaf (one cotyledon and one true leaf means two leaves). The ones that haven’t will likely be discarded. Of my 39 2017 Kelsae transplants, 38 have first true leaves on day 29.

Transplanting into the garden can happen from the equinox through to 21st April, depending on the spring weather and how far developed the young plants are. Early transplantation is accompanied by protecting the plants with fleece for a month, or until temperatures at night are around 8-10C.

My timetable for Kelsae onions this year was/is:

Sowing date: 5th February 2017

Transplantation date: 21st February 2017

Setting out date: April 1st or April 9th 2017.

IF you sow onion seed this week or next, you can still achieve good bulb sizes.


For an interesting read about some historically interesting contributors to the art of growing onions, try reading:

‘Growing Onions and Shallots’, Daniel A. Calderbank (Ross Anderson Publications) ISBN 0-86360-027-1, published 1986


March 2017 IV: Planning a 7.5 sqm bed for root crops

With a small garden of 50 sqm, using every square metre of soil productively is critical.

My four bed roation has broadly the following layout:

Bed I: potatoes

Bed II: Broad beans, leeks, beetroot, forcing carrots and lettuce

Bed III: Garlic, Runner beans, french beans, beetroot, June carrots

Bed IV: Parsnip, April and May carrots, onion.

Where space is available, additional salad, turnip, radish and fennel are slotted in for half a season.

This post discusses my root crop bed, how I plan it and why.

I start with parsnips, as these take a whole season to grow. My 2016/17 crop was 4 rows of 1.5m spaced at 40cm, with rows at 20cm, 60cm, 100cm and 140cm from the north end. The crop has yielded 8-12lb/ row and has if anything been slightly more than required for the whole winter. The roots have been up to 40cm long and up to 1.5lb in weight.

As a result, this year, I will only plant three rows, spaced at 20cm, 60cm and 100cm. I will be sowing Tender and True from Real Seeds.

Next I will sow three rows of carrots in early April, spaced at 130cm, 160cm and 190cm. Two rows will be Sweet Candle and one row will be Early Nantes.

Next I will transplant onions: 5 rows of Kelsae spaced at 20cm in an equilateral triangle lattice (220cm, 237.5cm, 255cm, 272.5cm and 290cm); 2 rows of van Rijnsburger clumps (325cm and 350cm latticed); and two rows of van Rijnsburger singles sown at 10cm spacing (370cm and 390cm).

Finally, 5 rows of carrots (Nantes) will be sown in early May (410, 430, 450, 470 and 490cm).

Target yields will be:

Parsnips: 30lb;

April Carrots: 20lb;

Onions: 50lb;

May Carrots: 30lb.

In addition, radish will be intersown between parsnip and April Carrots (5 rows) and as an early crop before May carrots (total radish target 5lb). After the onion harvest and April Nantes carrots, autumn salads will be grown (total target 15lb).

As a result, the target for the 7.5 sqm bed for the season will be 150lb.


March 2017 I: The outdoor tomato growing Season

Growing tomatoes outdoors in the UK requires a certain level of commitment.

For a start, the first 2 months of the ‘season’ are not outdoors, they need to take place indoors, or in a protected outdoor space such as a lean-to. Without the warmth and protection from wind, young tomato plants will not grow. With that protection, their growth rate is fairly astonishing.

The tomato season can be split into four phases:

  1. Germination of seeds.
  2. Vegetative growth prior the first flower emerging.
  3. Flowering and fruit set.
  4. Fruit growth and ripening.

By studying my tomato plants the past 5 years, I can say with confidence that most tomato strains, if sown in early March and grown indoors until late April/early May, will usually yield their first ripe tomato within 18 – 20 weeks.

One blog post is nowhere near enough to teach you how to grow tomatoes and there is a well-established blog where I learned much of my skill in growing tomatoes (www.tomatogrowing.co.uk ), produced by Mr Nick Chenhall, until recently based in the West Midlands but now relocated to Devon. If you want a weekly newsletter through the season giving tips on tomato growing, Nick’s website is your port of call.

My top tips are these:

  1. Germinate tomato seeds with plenty of heat: I place my seed trays on top of our outside gas boiler for 4 – 5 days and germination is uniformly excellent. Leaving them indoors at room temperature is less secure.
  2. Save your own seeds from plants which grew well in pots, outdoors, in your home area. You have selected seeds suited to your climate, not seeds created in China or wherever.
  3. Once you have found some favourites which work well, stick with them as bankers. My list of bankers includes Maskotka, Alicante, Super Marmande, Sungold and Tigerella.
  4. Spend one season documenting a few things about tomato plants each week – you will quickly learn that there is a pretty set timetable for tomato plant evolution from seed to ripe fruit. Things to look at are numbers of leaves and stems on young plants, number of trusses, flowers and fruit set on maturing plants and number of fruit harvested from mature plants.
  5. Be prepared to experiment: people who say that tomato plant pots should not be stood in water in high summer as it damages roots clearly have not done this in NW London – it generates fantastic crops! Tomatoes will absorb a gallon of water a day from beneath during warm sunny days of July and early August. Plants drying out is a far greater problem.

Here is a timetable which should work well for 2017:

  1. Sow seeds March 10th
  2. Pick seedlings to 8cm pots 20/21st March.
  3. Pot on to 15cm pots 16th April.
  4. Pot into final pots, 30cm diameter on 14 th May.

On that timetable, you may need to put plants in a shed, garage or the like if there are cold nights in the second half of May. However, tomato plants are hardy once established and will happily survive the odd night at 5C.