Cold Frame Blog

A brief history of cold frames

Sat, 20 Feb 2010 11:36:42 GMT

Where did cold frames come from?

Cold frames were originally designed as an adjunct to a heated greenhouse. The concept was that once the seedlings had been grown in the heated greenhouse, they could be hardened off in the adjoined unheated cold frame.

Traditional cold frame designs were planned when the greenhouse was build and the frame would have been incorporated into the brick foundations, frequently running along the whole length of one side. The cold frame was usually situated on the southern side of the greenhouse and may even have included a small door or hatch allowing access to the cold frame from within the greenhouse. All cold frames feature the ability to open the roof light (the glass lid of the cold frame), giving the ability to control the temperature relative to the outside environment.

Modern cold frames

Modern cold frames share the same features as their predecessors, the sloping glass roof, south facing position and the ability to open the roof light by varying degrees. These days, it is common to see cold frames used in isolation, both for the propagation and hardening off of young plants, frequently where there wouldn’t be enough space for a greenhouse. With the costs of heating greenhouses rising, many users are using soil warming cables and other methods to create so called “hot frames”. Ironically these hot frames are frequently used as an addition to an unheated greenhouse!

With renewed interest in vegetable gardening in recent years, cold frames have seen a comparable upsurge in usage, particularly as they are compact, inexpensive and easy to install. The ease of hardening off seedlings when using a cold frame coupled with the ability to grow crops earlier in the season makes a cold frame an excellent investment for any keen gardener.

Polycarbonate Cold Frame£39.99

Snow, garlic and yet more snow

Mon, 18 Jan 2010 20:51:27 GMT

What a strange 12 months of weather we have had, a near drought during the latter part of the summer and serious winter conditions during December and January. Such weather has made it more difficult to get into the garden and achieve anything; in fact the last of the snow only disappeared this weekend.

By some good fortune I have got myself organised and managed to get the garlic in the ground before over Christmas, this year, like last year I’m growing Solent Wight which is a relatively strong variety that thus far seems to have kept very well indeed.

Garlic Growing Tips

With the proper preparation, garlic can be one of the easiest crops to grow. The first step is to prepare the bed; I fork a good amount of garden compost into the bed after I have dug it over and then allow it to settle for a few weeks. I will then rake in some general purpose fertiliser such as blood fish and bone and cover the bed with weed control fabric. Take a sharp knife and cut a slit at the appropriate spacing (about 6 inches is good). As the soil should be fairly light from the raking you can simply push each clove into the ground, through the slit in the weed control fabric (pointy end up).

Apart from making sure the initial garlic stems come through the slits, there very little to do until harvesting in June – August, although you can add a mild general purpose fertiliser periodically during the growing season if you desire.

Garlic Solent Wight£4.75

Garlic Lautrec Wight£4.75

Rain at last!

Thu, 01 Oct 2009 15:37:24 GMT

I know many of you will have considered 2009 a pretty poor summer, but for those of us living in East Anglia, the weather has been warm and dry since May. This has been great for barbeques and the kids, but pretty poor for the garden. Particularly as I quickly loose enthusiasm about regular watering. So it was with some relief that I woke up this morning to what must be the first rain since July.

It has been so dry that the front lawn is all but dead (see picture) and I have lost four new asparagus plants due to the drought conditions. On the flip side the 5 chilli plants I transplanted to my seed bed have thrived, growing faster and bearing more fruit than the pot bound examples in the greenhouse.

Cold frame gardening?

Given the warm weather, the cold frame has seen very little use of late, although the night time chill is starting to be felt so it won’t be long before it gets some use. Time permitting, I intend to sow some lettuce in the cold frame in the next few weeks and see if I can manage to grow some winter lettuces this year.

What's in my cold frame this month?

Mon, 07 Sep 2009 20:54:02 GMT

Due to my previous disaster with my cold frame, there is still nothing growing in it, although I have managed to dry some onions in it.

As I have nothing to write about my cold frame I thought I may as well share a recipe that I cooked a couple of weeks ago using almost entirely ingredients from the garden.

Garden Vegetable Risotto

Ingredients
½ tbsp Olive Oil
3 Onions
4 Cloves of Garlic
8 Green Peppercorns
2 Red Chillies
4 Courgettes
4 Carrots
10 Runner Beans
½ tsp Black Pepper
1 tsp Basil
5 Fresh Tomatoes
500g Pork (or other meat)
300g Rice
Splash of Red Wine

Preparation

Cube the pork, chop the vegetables and chillies and crush the garlic and peppercorns. Wash the rice thoroughly and then place in a saucepan and cover well with water.
In a wok or large pan add the Olive Oil, onions and garlic and fry until they turn translucent.
Add the pork and chillies and chopped fresh tomatoes. Fry until the meat is cooked through
Add the remaining ingredients and bring the mixture to the boil, before reducing the heat and allowing it to simmer. Turn on the heat for the rice and allow to boil for about 10 minutes (until the rice has partially softened). Add the rice and water to the risotto and bring to the boil again.
Reduce the mixture until the rice is cooked and the sauce has thickened.

Serve and enjoy!

Polycarbonate Cold Frame£39.99

Holidays are not good for your garden!

Sun, 02 Aug 2009 09:22:44 GMT

A few days ago I arrived back from a short holiday and quickly realised that the end of July is not a good time of year for a gardener to go away. Despite having arranged a number of friends to do a spot of watering, the weather conspired to provide something like perfect growing conditions. Upon my return, the lawn had grown about 2 inches, half my cauliflowers had gone beyond their best, the peas had come and gone and my courgettes were the size of marrows. To add insult to injury, the weeds had also enjoyed the wet weather and I’ll need several hours just to get thinks back in shape.

Despite all of this, the garden has managed to produce a number of firsts for me.

Ridge cucumbers, very tasty despite their odd appearance
Tomatoes, I harvested my first small tomatoes having never grown them before.

The sweet corn that was planted in paper pots is doing amazingly well after the recent rain, some of the plants are over six foot tall and all have formed the beginnings of cobs. The stems have started to fall on the red onion and the garlic, although the multi-sown Bedfordshire champions seem to still be growing. The first chillies should be ready within the next week or so and it looks as though I will have a bumper crop this year. Looks like I’ll be eating a lot of curry this year!

I have found a new cold frame for the site, a FSC wooden cold frame with a double lid.

Whats in my cold frame this month?

Tue, 30 Jun 2009 22:40:36 GMT

Unfortunately there is absolutely nothing is in my cold frame this month.

Murder, murder they cried!

I'm ashamed to admit to mass homicide. Having thought that my cold frame was open, I didn't bother to check it for two days during the really hot, very sunny weather - you know temperatures of 30 degrees. Needless to say I hadn't left the cold frame open. So I have brutally killed my final batch of cauliflower and cabbage seedlings. It looked like the Sahara desert in the cold frame by the time I checked on it.

We all learn by our mistakes I suppose.

Polycarbonate Cold Frame£39.99

Father's Day Gift Ideas - 21 June 2009

Thu, 28 May 2009 22:11:28 GMT

It can be difficult to choose a good gift for father's day, for keen gardeners, I have selected a range of products that will be appreciated but without breaking the bank.

Father's Day Books

This was the book that got me interested in vegetable gardening. I was bought it one Christmas shortly after we'd moved to our current house. After reading the book, I cleared a space and set up a vegetable garden. Unlike many gardening books, it is entirely possible to read this one from cover to cover. An ideal present for someone relatively new to vegetable gardening as it details not only how to grow, but when to grow and how to eat. It also contains sections on general gardening techniques such as composting, greenhouses and cold frames.

The Vegetable and Herb Expert is a great reference book for the more experienced gardener, it is well indexed and provides detailed pages on just about every type of vegetable and herb, including several that technicall are fruits, tomatoes, chillies etc. The information is clearly presented on each page and clearly states when to plant, how to plant and the general maintenance required.

The Organic Fruit and Vegetable Gardeners Year is a very different book, from the previous two, being organised by time of year. As you would expect from its title its focus is on organic gardening and includes a number of helpful hints on topics such as organic pest control. The main book is split into four sections corresponding to the seasons. Being organised in this way makes it very useful as an aide-memoire for your gardening tasks.

Father's Days Gardening Tools

What better present for your father than tools! Every man takes great pleasure in filling their shed or garage with them! This trowel and fork set is the perfect addition to any gardeners arsenal. These heavy duty stainless steel tools will last for years and are ideal for those small jobs like plant out, potting on and even pulling carrots.

Gardening gloves are one of those items that gardeners are always in need of and if I'm anything to go by they very rarely buy them. These are the heavy duty version, ideal for pulling up nettles, brambles and just about anything. However they also make a lighter weight version designed for the finer work such as weeding around seedlings.

Father's Day Cold Frame or Cloche

If you want to spend a little more on your Dad, why not treat him to a cold frame - this is a site about cold frame gardening after all! If he doesn't already have one and maybe even if he does, a cold frame makes a great gift that lasts for years and has a real functional value. If you want to really treat your father, why not go for one of the very attractive wooden cold frames?

If on the other hand you father has a cold frame (or more than one) maybe you could buy him one of our many cloches, either the attractive victorian styled cloches or one of the poly tunnel style ones.

Hawthorns Classic Coldframe£96.70

Easy Poly Tunnel x1£24.99

Paper Pots for your Coldframe

Mon, 18 May 2009 22:45:24 GMT

Having spent a frustrating few hours attempting to remove seedlings from small module trays without damaging the roots, and being largely unsuccessful, I happened to stumble upon a forum post about paper pots.

The idea is to make pots from old newspaper, once the seedlings have grown and been hardened off in your garden cold frame the whole pot can be planted into the ground, allowing you to transplant without root disturbance. In this way the paper pots work exactly the same way as the peat pots that I keep threatening to try and never get round to.

My 2 1/2 year old daughter and I spent and pleasant hour or so making paper pots in the garden, she thought it was great fun and amazingly it managed to hold her attention for most of the hour.

To make your own paper pots, its pretty simple:

Take a single page of a tabloid newspaper and an aerosol can (preferably empty)
Fold it in half from top to bottom and then again – it should be about 1/2 the length of the can
With about 1/3 of the paper overhanging the bottom of the can, roll the paper around the can.
Fold and push the paper into the indentation at the bottom of the can.
Remove the paper and you have a pot!

A full description of the process with pictures is available here.

I have been really pleased with them, rather than trying to extricate sweet corn seedlings from module trays without disturbing the roots (almost impossible and time consuming) I simply popped the pots straight from the cold frame and into the soil. No root disturbance and really quick to do.

What's in my cold frame this month?

Thu, 07 May 2009 23:03:59 GMT

The multi-sown onions successfully made it into the vegetable patch and seem to be fairly happy in their new environment, although I have had to be pretty keen with the watering can recently due to the almost drought like conditions we have been having in the East of England.

Unfortunately I have managed to nearly kill the chillies that I had over wintered – the combination of gloriously sunny days in a closed green house followed by overwatering and then a greenfly infestation has left them looking rather ill. I’m hoping that I have rectified my ways early enough to for them to survive.

The cauliflower and cabbage seedlings came out of the cold frame this week and have been quickly replaced by the runner beans and sweet corn that is ready to be hardened off. Recently I have been so frustrated trying to get seedlings out of module trays without damaging the roots that I decided to try using paper pots this year for my runners and sweet corn. I’ll tell you all about it in a future post.

Having looked at my post from last month, I have realised that I have completely forgotten to sow any spring onions. Well it doesn’t look like I’ll have any ready to put in the potato salad with my first crop of earlies then.

Apart from sowing spring onions, I want to make a wooden frame to attach netting to. Ideally it will have a hinged, or otherwise removable top so that I can get to the brassicas while keeping the pigeons and cabbage whites out. Too much to do and too little time as always. For the time being I have a couple of cheap cloches protecting the cabbages and cauliflower. Which will keep the pigeons away as they’re the major threat at the moment.

Carrot Root Fly

Thu, 30 Apr 2009 23:19:04 GMT

May is nearly upon us, which means it’s nearly carrot root fly season again. Carrot fly attacks can range from merely a minor inconvenience to a full-scale disaster depending upon when they strike. Typically they strike when you’re thinning out the carrots as they are attracted by the smell. Unfortunately this is the very time when the carrot fly does the most damage to your harvest. However you don’t have to suffer, there are a number of ways of keeping the carrot flies at bay.

Companion Planting

Some gardeners swear by growing carrots and onions together, claiming that the smell of the onion deters the carrot fly and the smell of the carrots deter the onion fly. I cannot comment on how effective this is, as I’ve never attempted it. Its always seemed a little hit and miss to me.

Seasonal Timing

The female carrot flies lay their eggs around May, this batch of larvae eats its way through your carrots before then being ready to start laying more eggs in August. Therefore it is possible to sow carrots late – mid May, and avoid the first batch of the carrot root fly. Once the second batch comes around you will hopefully be in a position to start harvesting them.

Fencing them Out

Carrot root flies aren’t very good at flying, strange as it may sound. They will only fly about 18 inches (45 cm) above the ground. As a result, it is perfectly possible to fence the carrot flies out, simply by erecting a barrier that is about 2 foot tall. I tend to use polythene for this purpose, as it’s cheap and effective. However there are fine meshes that do the same job, whilst being more resilient than polythene, not to mention being better looking! Why not take a look at our range of netting and mesh suitable for keeping out carrot fly.

Root Fly Netting Cabbage and Carrot£24.95

HEAVY DUTY UV POLYTHENE 2MX6M£13.99

Cloches in your Garden

Fri, 24 Apr 2009 23:35:17 GMT

Cloches can be a useful addition to any garden, from a humble poly tunnel style cloche to a great looking bell cloche. Not only can cloches allow you to protect plants during our colder months, but they can help protect against pests as well.

This year I have sown a catch crop of radishes within my parsnips. However a few days after the radishes came up I spied a pigeon eating them. Spotting this, I rushed to cover the crop in an inexpensive poly tunnel style cloche and it seems the radishes have recovered without too many issues.

Many people forget that cloches aren’t just about warmth, in fact they are probably better at keeping the nasty weather out than keeping the warmth in. Several days of prolonged rain can be catastrophic to a newly planted crop of sweet corn, stunting their growth or maybe even causing them die. If they’re covered with a cloche the vast majority of the water is kept away from their stems and roots therefore preventing rot from setting in.

Although I am a huge fan of the poly tunnel style cloches due to their ease of use and ability to be stored easily, they are not the most attractive things. There is an answer, I have located a range of Victorian style bell cloches, although these only cover a single plant, they look stunning and are perfect for your early lettuces.

Hardening Off

Sun, 12 Apr 2009 18:45:55 GMT

A lot is written with reference to "hardening off". In fact you can hardly read any gardening book without seeing the term. When I first started gardening (only a few years ago) it was a term that confused me and didn't seem to be explained anywhere.

What is hardening off?

In essence hardening off is simply the process of acclimatising a young plant or seedling that has been grown under glass or indoors to cooler outside temperatures.

Why harden off?

Many plants are prone to significant checks in growth if they are moved straight from a warm cosseted environment (such as a greenhouse or propagator) directly to their outside location. If the weather is kind to you, you’ll probably get away with it, however if you have even a minor cold snap then you could be in trouble.

Cauliflower in particular is prone to these checks in growth and can frequently cause the plant never to develop full sized heads, leaving you with golf ball sized cauliflowers.

Last year my sweet corn suffered because I didn’t follow my own advice and planted directly from a greenhouse to outside. I stupidly thought early June would be okay weather wise. What happened was of course that we then had about two weeks of solid rain and cold weather. The result was that only about half the crop grew to a useable size with some of the plants dying and rotting where they stood.

How to harden off?

Without a cold frame, the standard procedure for hardening off is pretty laborious. You place the plant outside for perhaps an hour on the first day and then bring it back inside. You repeat this slowly increasing the amount of time it spends outside until it is outside for most of the day. At which point it can then be transplanted to its permanent position outside.

This process is fine if you have plenty of time on your hands, however if you work this process can be nearly impossible.

Hardening off the easy way - A cold frame

If you have a cold frame, it becomes incredibly easy to harden off your seedlings. The basics are simple, on day one start with the roof light of the cold frame just slightly ajar and over the course of the next couple of weeks raise the light a little higher each day. After a couple of weeks the roof light should be fully opened and the plant is now hardened off and ready to be transplanted.

The added advantage of using a cold frame to harden off your plants is that the plants remain much more protected from the elements, such as heavy rain and strong winds while they are getting used to the change in temperature.

Polycarbonate Glazed Cold Frame£59.95

What's in my cold frame this month?

Sat, 11 Apr 2009 23:41:45 GMT

Its Easter, the traditional time for planting potatoes and in accordance with this age-old rule the last two rows of my Pentland Javelins were planted out yesterday. Given the relatively warm weather recently I started my potato planting a little earlier than usual in March.

The radishes are up, along with the asparagus, which was newly planted in March and the leeks are doing well in the seedbed.

The onions came out of the cold frame yesterday due to the unseasonably warm weather. They will be outside during the day from now on and in the greenhouse at nights with a view to planting them on mid next week. This means that my cold frame is empty currently, although only for the next couple of days until the cauliflower seedlings are ready to go in and be hardened off.

As usual for this time of year, I seem to be running behind my schedule and I’ve still got a huge list of garden chores left to do:

Sow spring onions
Sow lettuce
Sow peas
Sow more carrots
Erect wigwams for runner beans

At least I have managed to prepare all of the beds and done many of the potting tasks that I needed to do. Normally around this time I realise that I have forgotten at least one type of seed. If it has happened to you, don't worry, pop along to Thompson & Morgan, I'm certain they'll have what you want.

Polycarbonate Cold Frame£39.99

Early Cauliflowers in your Cold Frame

Tue, 07 Apr 2009 18:57:40 GMT

Wouldn't it be nice to have a fresh from the garden cauliflower in June? Long before vegetables were routinely flown in from Africa, gardeners all over the UK used to do just that. In fact with cold frames, cloches and modern cultivars it is very nearly possible to eat fresh cauliflower all year round.

Plant the seeds into your cold frame towards the end of October. The seedlings should be overwintered in the cold frame and come the end of February you should be able to harden off the seedlings. Arround this time set up your cloche over the bed where the cauliflower will go to allow the soil to warm. After a couple of weeks you can plant out the seedlings, underneath the cloche. At this point you can also start off your maincrop cauliflower seeds in the cold frame.

With the cauliflowers under the cloche, ensure you keep to the usual routine of brassica care, including watering, feeding etc. Come early June the heads should be starting to form. At this statge its worthwhile remembering that you can harvest them whie they are still small and they're still very tasty. Doing this obviously helps to reduce the glut that will enevitiably happen otherwise.

Done correctly, it is simple to have fresh home grown cauliflower from June until late October. Yum!

Slug Control

Thu, 02 Apr 2009 19:03:34 GMT

You spend hours carefully planting your cauliflower seeds. You monitor their temperature carefully and water just the right amount. A few weeks later you're rewarded with your seedlings that are now ready to go into your cold frame to be hardened off.

People have told you how hard cauliflowers are to grow, but things are going really well and you're feeling confident. Over the weeks you slowly open the lights on the cold frame and before you know it your ready to plant out.

Having read about cabbage root fly you sensibly purchase some cabbage collars and plant out. You then see some pigeons around so you rush out to buy a net cloche.

After months of hard work the heads have formed and you say to yourself, "I'll harvest the first one tomorrow". So the next day practically salivating at the thought of fresh cauliflower you go to your vegetable garden to find something like the picture to the left.

Sodding Slugs

My exact language when this happened last year might have been slightly more "rich", but I'm certain you can appreciate how I felt. Over the next few months I fought a losing battle against the slugs in an effort to protect the remaining crop of brassicas.

Preemptive Strike

This year I'm planning a preemptive strike on the resident slug population. Having done a great deal of reading I have decided that nematodes are the answer. Phasmarhabditis hermaphrodita is apparently the gardeners best friend, being a nematode that feeds exlusively on slugs. It is naturally occuring in the UK and has no effect on any other species.

In the UK it is commercialised under the name nemaslug and is available in both a small (40 sq metre) and large (100 sq metre) packs. If you have slugs, don't suffer the heartache that I had last year, buy yourselve some nemaslug and sleep easily. I have!

We have sourced nemaslug at the cheapest price we could find on the internet, why not buy yours today.

Nemaslug Slug Killer 100m2 Large Pack£19.95

Nemaslug Slug Killer 40m2 Regular Pack£9.95

Cloche or cold frame? Which should I buy?

Tue, 31 Mar 2009 19:59:11 GMT

In an ideal world I would suggest both as they fit different purposes, but if you really have to decide on one or the other I have compiled a list of their respective benefits.

Cold Frame	Cloche
Permanent / Semi Permanent Ventilation adjutable More Expensive More Robust	Moveable No Ventilation Adjustment Cheaper Less Robust

The cold frame's fixed location and adjustable ventilation make it ideal for hardening off plants that have come from either the greenhouse or indoors. The ability to progressively open the roof light more each day allow a gradual acclimatisation. Also wooden cold frames in particular are better a retaining heat during the night.

Cold frames tend to be of a more solid construction and heavier meaning that they are more resilliant to wind and other damaging factors. However their increased weight and permament nature means that they are exposed to the worst of the weather whereas a cloche can be brought indoors. Also as a cloche is moveable it can be moved to different areas of the garden as the need arises.

Finally, cloches are generally cheaper, particularly polythene tunnel cloches. Although the polythene on these cloches tends to deteriorate over time they can be an inexpensive way to get large swathes of you garden off to an early start.

In summary, if you want to extend the growing season and harden off seedlings then buy a cold frame. However if you want something to aid germination directly in your garden, then a cloche is probably the answer.

Polycarbonate Glazed Cold Frame£59.95

Easy Poly Tunnel x1£24.99

Growing onions from seed

Fri, 27 Mar 2009 20:46:28 GMT

Why?

This is the question I get asked most. Why not grow from sets? Part of it for me is that I like the challenge of growing from seed and it gives you something to plant in January. However the main reason for growing from seed is that you can buy varieties that you cannot find available as sets. And if you're a frugal gardener, they also have the added advantage that they are cheaper.

How?

I sow the onion seed into seed trays filled with seed compost at the end of January and place in an electric propagator. Within a week or two they should have germinated. At this point you will want to ensure that they get plenty of light otherwise they can go a bit "leggy".
By March, the seedlings can go into an unheated greenhouse or cold frame and be hardened off ready to be planted out in April.

This year I am experimenting with "multi-sown" onions - basically a nice term for being lazy and sowing in modules with 3-5 seeds in each module. They are then planted in "clumps" without any need for thinning out.

What's in my cold frame this month?

Thu, 26 Mar 2009 20:16:28 GMT

Well March is traditionally the time when things start to get really busy in the garden. The end of March and beginning of April is when my wife starts to moan about me spending more time in the garden than in the house.

We have been lucky so far in that March seems to have been pretty mild with some lovely sunny days. Its certainly been sunny enough that two chili plants in my greenhouse are bearing fruit.

However, back to the cold frame, it currently has two trays of onion seedling in which are enjoying the sunlight and the warmth of being in the cold frame. Sadly this is my second batch of onions as the first batch was destroyed by the winds in early March that turned most of my vegetable patch upside down.

I had hoped to have some cauliflowers in the cold frame by now but due to the wind incident the cauliflower has had a later start in the seed bed as the onions are still in the cold frame.

In a week or so it will be time to open the cold frame a little and harden off the onions before planting them out.

How to choose a cold frame

Tue, 24 Mar 2009 20:24:18 GMT

There are so many different designs of cold frame available; using different materials it can be a little overwhelming.

Construction

The initial choice is really between wood and aluminium (or other metal) construction. Wooden cold frames are more suited to a permanent site due to their heavier weight; they are also more attractive in my opinion. Aluminium cold frames are great if you want to be able to move them: to take advantage of the seasonal changes in the suns position for instance. Wood has the added advantage that it retains heat better and will therefore keep your precious seedlings warm well into the night.

Glazing

Traditionally cold frames used horticultural glass however it is pretty rare to find a new one using glass. Modern cold frames tend to use polycarbonate that is considered to transmit light just as well as glass. Glass has the advantage that it is a better insulator. However double-glazed cold frames using polycarbonate are available that mitigate this. The big advantage of polycarbonate over glass is that it doesn’t shatter which is vitally important if you have children or pets. Polycarbonate is also cheaper and lighter than glass.

Design / Style

There are two main designs, those with the traditional sloped roof light and those with sliding roof lights. I prefer the traditional style of cold frame with the sloped roof light as this helps to keep the weather out even when left partially open. Of course the sloped roof is more susceptible to wind than the sliding variety when open. Generally aluminium cold frames are fully glazed (i.e. the sidewalls are glazed) whereas some wooden cold frames have solid wooden walls, giving better night-time heat retention.

Polycarbonate Cold Frame£39.99