ROOF TOP VEG PLOT

October Carrots

It has taken me a while to get the hang of carrots.  Considering that they are one of our native species and that they grow wild almost anywhere that is a bit embarrassing.   However, in gardening we learn by our mistakes. Over the years I’ve found ways of growing quite respectable carrots on the rooftop.

Even though carrots are cheap to buy in the supermarket, the smell and flavour of an early variety taken straight from soil to plate is irresistible.  And now that they are cites as having so many health benefits, they seem a must for the rooftopvegplot. In other words, a bit of care with the soil preparation and sewing will repay dividends later in the year.

The recent introduction of new varieties mean that carrots can be cropped almost all year round.  They are a cool season crop, enjoying the shadier autumnal world that the heat of summer, so on the roof top – where it can get a bit Mediterranean in summer - I think the autumn planting is preferable.  (Though a few square feet of spring carrots add deliciously to the first summer salads.)

Soil Depth
Carrots, even the small round ones have long taproots, and these like turnips and other roots crops mean that only very average results can be achieved in my shallow raised beds.  I have found far more benefit from growing carrots in deep pots, the same pots that I use in summer for potatoes.  These are about 400mm across and 450mm deep.

Carrots sprouting

Soil Type
Carrots require a nutritious, well drained and sandy soil.  They don’t like newly manured ground and they don’t like stones.  So soil preparation is important.   It is better to provide the seedlings with a slightly impoverished soil and then feed regularly with a seaweed wash or a liquid tea.  Niki Jabbour swears by a little wood ash sprinkled in the planting trough.  This she advises will bring the acidity up a bit, and they like a slightly acid soil.

Varieties
There are a worrying diversity of carrot varieties.  Frankly, for spring sewing just about anything will do, as long as you have deep enough pots.  The competition growers grow carrots in deep oil drums filled almost completely with sand.  But for us mortals, on a smaller scale, the early varieties and the miniature types do well.  All of the varieties below can be planted in a cold frame or hoop tunnel 8-12 weeks before the first frosts.  For London that gives a last reliable planting date of early October, but in a good year you can risk planting up until November in a sheltered and sunny spot. 

I found this very good diagram of carrot shapes,  which is helpful when choosing your variety.  I find that the images in the seed catalogues are not always helpful.  THey are never to scale so the Imperator looks just like the Amsterdam! Carrots don’t mind too much about low light levels, so they do not suffer too much at the ten hour cut-off date, October 25^th in London.  But the seed must be fresh.  THis is one occasion when last years seed packet won't do.

• Nantes is a small early and fast maturing carrot.  As it is a stalwart in the carrot world, I can also find it sold on seed tapes or as pelleted seeds (both useful for the heavy handed broadcaster – see below)
• Mignon (12 weeks) is fast growing and recommended as a baby carrot.
• Mokum F1 hybrid, a larger variety that is supposed to like snuggling with its cousins in a deep pot.
• Parmex – the favourite of Nikki Jabbour, these are small and round, and will, according to the catalogues, even crop in a window box. (I’ll have to try that)
• Purple Haze are frighteningly bright purple.  They are bigger than the other recommended varieties so consequently need a deeper pot.
• Chantenay, are and old variety of short, fat and stubby carrots, so excellent for shallower ground.  Thompson and Morgan do a cultivar called Supreme.

 

Just a tiny carrot, but already a long root

Sowing
Sowing carrot seed requires some care.  If the seed is old, they will not germinate. If they are planted too close, they will not come up.  If the soil is too wet and sticky, they will not come up.  If they get too much sun and dry out, they will not come up.  If there are weeds in the mix, and you are not vigilant, they will not come up!

Some people suggest sowing radishes with the carrots, this thins the spacing and because the aeration of the soil as the fast growing radishes are plucked, is good for the carrots.  Others swear by seed tapes or mats.  But good varieties are often difficult to find.  Suttons do a seed tape for Nantes and Amsterdam (another early variety) and Bakers do a mixed radish and carrot tape (for spring).  I haven’t found a supplier of seed mat for carrots, in traditional gardens they are sewn in rows.  But I have tried making my own with kitchen paper and flour and water glue.  There is a nice how to guide in Annies Kitchen Garden Blogspot 

It is also important to keep the seeds shaded until they come up. I place a newspaper mat over the top until they’ve come through.  However I havent found the technique to be foolproffo.  

My experiment with Kale seeds produced less than perfect germination.  I wondered whether the slugs had feasted on the glue.  I dididnt leave the sheet to dry before planting - any thoughts readers?

Kale seeds suspended in a flour and water paste, on kitchen paper.

Cultivation
if all this detailed sewing instructions has put you off carrots, the good news is that from now on it is plain sailing.  Feed occasionally, make sure the automatic watering is working and weed out any rogue that seeks to crowd out the crop.  As long as the pots don’t dry out they should be fine.  The foliage looks lovely and does the work of shading for the plant, so there is no need to find too shady a spot, even in high summer.

Carrot seedlings at a good spacing once thinned. Note the rocket catch crop planted around the edge.

Harvesting
Carrots keep for ages in the soil, so there isn’t much point in succession sewing.  Start cropping intermittently, as soon as they are large enough to eat, leaving the in between plants to grow larger as they are given more soil-space.

Pests
Carrot root fly should not be a problem on a roof top garden, the critters don’t fly high.  But to be on the safe side from late spring to later summer they can be shaded with Enviromesh, or a fleece.  

November Garlic

The crop from one bulb of garlic. 2013

My flower bulbs were planted way back in September, but there is one bulb that prefers to be planted later on in the year.  That is garlic.  It is about the easiest thing to plant.  Break a globe into segments and then push them gently into the soil, burying them about 50mm below the surface. The books say plant 200mm apart, but I plant them far more closely, probably about 120mm in both directions. If some of the bulbs are a bit small they can be planted together and will form a nice cluster by next autumn.  Garlic can also be planted more closely together and then thinned in the spring to provide a tasty spring onion like crop.  However this practice might compromise the size of the ones left in the ground to mature.

Garlic grows well in my veg plot.  They don’t take up much space, and because they are slow growers, they can be inter-planted in early summer with leaf crops.  Leave the plants to fend for themselves in a sunny spot and by August/September you will find that the foliage begins to die down.  By then, below the soil surface, each bulb will have transformed itself into a fat globe.  If I get a good crop I save the fattest for planting next year.

There is some evidence that garlic is a very locally sensitive crop.  So by selecting the best globe each year, and replanting it, I should be able to develop a local cultivar.  I’m hoping that I will eventually be able to market a “Chateau Vegplot” variety.

There are two different types, hard-top and soft-top.

Hard-neck garlic – this is the type of garlic that can be purchased in the supermarket.  In fact, as long as the garlic you buy comes from a British grower, then it should be possible to plant it out in the garden.  It doesn’t set seed, so all the goodness will go into the bulb.  However it is not so pretty in the vegplot as soft-neck.

Soft-neck garlic, Allium sativium,gives two crops. It grows more leaf and it will flower.  In mid-summer the young leaves and flowers are delicious, if lightly stewed. Cutting them does not seem to harm the bulb below the soil, though I do leave a good proportion of the green stem intact.  These are called scantlings, or scapes in some parts of the country. 

Scantlings in mid june in a wet summer

However soft-neck garlic that looks to me identical to its hard neck variety, does not keep as well as the hard neck.  I like garlic; Early Purple Wight that comes from the famous garlic farm on the Isle of Wight.   It has a lovely purple skin and does crop early if planted out in the autumn.

If you leave the flowers in place you will be rewarded in good years by a constellation of bulb-lets around the flower.  This looks pretty and they can be eaten, but if sewn and left for two years they will turn into garlic bulbs. I’ve never tried this. 

Garlic bulblets from jimmycrackedcorn/wordpress

Garlic likes a period of chill, hence the autumn planting can increase yields, though some varieties have been produced for spring planting.  So if something dire happens to the autumn crop, don’t despair.

There is also elephant garlic, a massive bulb that turns into a monster, but its roots go down well below the globe, so I wouldn’t recommend it for shallow growing conditions.  

October Maintaining Soil Fertility

Ah, The Good Old Days! Gardening always has a whiff of nostalgia about it.  I remember the time when all vegetables, save winter cabbage, sprouts and leeks, were carefully lifted from the ground and gardeners would dig away merrily during the autumn days in order to allow winter frosts to break up very sticky clods. No-one worried much about fertility.  Allotments were spacious, fertilizer was cheap and we didn’t cross our fingers in fear if anyone mentioned super-phosphates.

But the roof top veg plot has very different requirements.  I grow organically; I irrigate (which can leach goodness out of the soil); I intercrop and I plant salads as tightly as possible.  I see bare earth as a sin and any planter more than six inches deep as a gift from God.  So during the month of October, when I’m taking out spent summer crops and re-planting, is a good time to consider increasing soil fertility.

Soil fertility is a complex issue, far too complex to cover in just one blog article, so I shall concentrate on some of the methods that work well for the rooftop.

Mulching
Last year’s fallen leaves, straw or grass cuttings all make excellent mulching materials.  You can buy forest bark in various stages of decay that also makes excellent mulch.  But mulching is not feeding.  In fact bark and fallen leaves, though they will rot down to improve the soil will leach out nutrients as they do so. So beware of mulching around crops that need all the nitrogen they can get. 

Last year I spread leaves over my fallow raised beds, but then discovered that a covering is essential, as they do tend to fly away. 

Never mulch seed beds or seedlings, they won’t like it. 

Mulching can tend to attract slugs as well, though I guess if they are eating your mulch they will be less attracted to lettuces on bare soil nearby.

The mulch does keep in moisture, so straw laid around the courgettes in mid-summer, or under strawberries as they crop can improve yields as well as protecting the crop.  Straw before it has rotted down is too itchy for slugs, so it keep them off, but as soon as the material starts to rot slugs will be attracted to all that putrefying mess.

Overwintering Meteor peas, under a straw bed and fleece

Feeding

During the summer I buy liquid feeds. The seaweed one is my favourite commercial variety.  If you want to get technical there are different mixes to encourage leaf production, strong roots or fruit. I also gather worm tea from my compost bin.  Incidentally, the easiest way to make a litre of liquid plant food is to put all your kitchen waste into a plastic bag and tie the tops together.  After about a month you will see the brown uggy liquid collecting in the base of the bag.  Simply snip off a corner over a milk bottle and let the amber nectar ooze out.   The partly decomposing waste can now be placed into the compost heap, taking up far less room that it would have done previously.

I’ve also seen buckets with a permeable centre cylinder.  The idea is that you pack the cylinder with nettles or comfrey, fill the whole thing with water, wait a few weeks for the whole lot to rot down, then pour.  A good tip is that the nastier it smells, the better it is.

These all work very well for a quick boost, but they don’t have the umph for a more through boost.   If I’ve been growing hungry crops like tomatoes or calabrese and I do have some fallow time, I can sprinkle with chicken pellets.  These dried dung-bombs are odourless and easy to handle.  But beware; chicken pellets can’t be placed directly around root growth, because they will burn it.  However they can be sprinkled into the compost heap, perhaps after emptying all that spent potato soil in there?

Composting

Decaying kitchen waste in the insultated compost bin. Note plenty of already composted material and spent soil to cover this up.

Home-made compost is one of the best mulches for my roof top plot because I can plant it up straight away. It improves the soil and, as long as it is the product of green and brown waste (leaves and stems) it will have a good mix of nutrients.  I shall be clearing my tomato and carrot beds this month.  Before I start I shall clear all the good compost out of the compost box and bag it up.  Then I will have room for spent soil from the beds and pots that can go straight into the compost heap, mixed with a nice proportion of chicken pellets.  That will be okay to use within about a month, but my winter needs will be rather modest by then anyway.  Then I shall mix some compost from the bags into the spent soil.  I may also add some vermiculite to increase the water retentive qualities of the soil, or expanded coya to lighten the soil.  I can plants seedlings directly into this mix and they will get away well.

My compost always has a lot of egg shells in it.  We run a B&B and get through hundreds of organic free range eggs every month.  I crush these into the compost, but they often don’t break down straight away.  Never mind.  The slugs hate finding egg shells in their paths, the compost worms make little houses out of them and egg shells have been shown to be better than lime in long term field tests.  As egg shells break down they slowly release lime into the soil. That will help to balance the acidity of my pots and raised beds, keeping them sweet and helping ensure that the plants can take up other nutrients I place in the soil mix.

The compost bin was one of the first elements that we put in when we went over to veg growing.

The books recommend that you buy special compost worms to populate your heap, but my worms have arrived quite naturally.  I dont know where they come from, but they seem to survive quite happily.  I provide them with straw for nesting in and I do water the heap if it seems dry.  I also have a problem with slugs in the heap.  I let them live for a while, but my firnd the compost guro, Mr Compost inspected the heap recently and pronounced the slugs a danger.
"They'l lay their eggs in there," he said.
So now, much against my nature I squash any I see.  Slugs are predated by nematodes, small wriggly worms, that I've also seen in the heap. So with a bit of luck the system will right itself.

Red wrigglers have entered the compost from somewhere

Fixing Nitrogen
Climbing beans, peas and sweet peas are over now.  I’ve left a few runners on the vine for seeds and dried beans, but soon I will start to clear them away as well.  However I won’t pull the roots.  Instead I shall cut the vines off at soil level, and mix in compost with the spent roots of the legumes.  If I look closely I will see pale grey nodules about the size of pepper corns clinging to these leguminous roots.  This is the nitrogen that this clever little family of plants produce, or fix.  And because it is natural, it won’t harm an immediate planting of tender salads or seeds.  Nitrogen is just what they need in order to produce green, leafy growth.

Peas crop early in the season and then leave a residue of nitrogen for a following crop.

Woodash
I now burn wood briquettes and logs in my fire, instead of smokeless fuel.  If you have an open fire, or you can burn the woody waste from the garden in a barbeque, this makes another wonderful mulch.  Ash from wood fires can be a useful additive to the compost heap or can be applied directly to fallow ground and dug in. It provides a natural source of potassium, associated with flowering and fruiting and it contains useful trace elements. Like egg shells, it also has a liming effect, so wood ash can remedy the excessive acidity that always tends to form in pots and raised beds. 

September Chinese Leaves

Mizuna grown from seed and ready for cutting in June after about 50 days.

Unless the spring weather is poor, I often find that a spring sewing of Chinese Leaves, as they have become collectively known, can be disappointing.  All my seeds come up and look brilliant for a week or two, only to grow tall, leggy stems and burst into flower.  Sometimes the rot can be stopped with a brisk haircut, rocket and spinach beet both respond well, but for Chinese leaves there seems to be no way to stop their busy progression into flowering.

Sowing these seeds in the autumn, or planting plug plants, as land becomes available, can provide very satisfactory, not to mention almost instant, results.  

If I decide to plant plugs, I will choose my supplier carefully.  Plug plants are much more delicate than a packet of seeds.  And take note of the varieties.  I do find that plug plant merchants can be a bit cavalier about varieties.  The rooftopvegplotter cannot afford to be vague on these points.  Some cultivars just don't work high up exposed to all weathers and with only 150mm of soil for comfort. 

Pak Choi and mizuna are both favourites of mine. They grow quickly and taste delicious.  Mizuna grows well as a cut and come again crop for the autumn, augmenting salads or providing greens for stir fry.  Pak Choi are, in my view, better than cabbage.  They don't attract slugs and butterflies as much and they are in, up and harvested before a cabbage had even germinated.  I haven't found them to be good as cut and come again, preferring to harvest them whole and cook them as a cabbage substitute.  

Mini greens are welcome in the depths of winter.  here lambs lettuce and watercress in November

When I order plug plants I try to find out when they will arrive and check the weather forecast and my social diary before ordering.  For once the little darlings arrive, speed and efficiency will be of the essence.  Unwrap the packaging immediately and give each plant a bit if water.  (Don’t deluge them.) Then plant out into prepared soil AS QUICKLY AS POSSIBLE.  It takes seconds to plant them out, so there is no excuse for dawdling.  Sprinkle a few slug pellets in any slug hidey-holes nearby.  I don't sprinkle the pellets around the new plants, that would act as a lure!  I want the pellets to act as decoys, not red rags to tell bull slugs where they can feast on new plants.  If I am sowing at the back of the season, I trim anything surrounding the nursery bed to ensure that it gets a good supply of sunlight.  Sun angles start to drop sharply at the end of August.  

Though you can start sowing Chinese leaves as soon after the summer solstice as you like, they can be sewn right through September, October and November.  Some people even say that by adding a little heat and a grow light that they can continue to be sown in the evil cold months of December and January. 

But whenever I plant, I find that by the end of September, it is safer to sow the seeds in trays, so that the seedlings can be moved into the growhouse as the weather worsens.  Because these are cold weather crops they do not rely so much on the high levels of lights that summer vegetables prefer, they will continue to grow well over winter, and because they have slightly tougher leaves than lettuces they don’t sulk in cold weather.  Most of them will, in fact survive, a light frost or snowfall. 

I take no chances with Chinese leaves, preferring the tried and tested varieties.  My top four varieties are:

• Pak Choi; China – a mid-green leaf that grows to a good size.  The shiny leaves of the Tatsoi and the Red Choi both look good, but I’ve had less success with the crop.
• Pak Choi; Baby Green – same colouring as China, but produces smaller rosettes, that can be sewn later in the season.
• Mizuna; Kyoto – vigorous and a good cropper. 
• Mustard; Giant Red – not strictly speaking a Chinese leaf, but can be treated in just the same way.  The pungent and deliciously coloured pinkish leaves give a hint of tanginess to autumn and winter salads.
  
  

  Seedlings of Pak Choi can be eaten like this, or potted on to heart up.