Pests and diseases

Natural and organic pest control tips

Cabbage white butterflyOrganic gardening has many advantages over a chemical based approach; the crops produced are tastier and more healthy but the other thing I like about it is it makes us understand nature better. Organic growing is more about avoiding pests or disease rather than applying a fix, it is about prevention rather than cure. To do this we need a little knowledge about our enemies which in turn gives us a deeper understanding of our garden and of nature’s cycles.

Which reminds me, I met an interesting guy last year, Andy Middleton, who own and runs an outdoor adventure business in Wales which I thought had a great ethos. Andy invented the sport ‘Coasteering’ which involves bringing wetsuit and crash helmet clad groups on trips along the Welsh coastline both in and out of the water.

The trip often includes a literal leap of faith from a cliff top into the foaming water below but not before you have been educated on timing the waves and learning when it is safe to jump. Andy likes to focus on parents and to teach them some basic outdoor skills designed to give them the confidence to bring their children on their own outdoor adventures.

Andy MiddletonThe thinking behind the fun/educational approach is that the more we and our children understand about our natural world and the more invested we are in it, the more likely we are to look after it. I guess organic vegetable growing shares many of the same principles as we learn to work with and respect nature in our pursuit of a healthy harvest.

By the way, the sport of Coasteering has become increasingly popular and is available all over the British Isles if you’re up for an adventure, you can click on Andy’s video for his TYF group above if you want to see what it’s all about.

Back to the point…
As we’ve said a natural approach to growing is about trying to avoid pests or disease. Creating a well fed and healthy soil is the corner stone, after that is is about smart sowing times, crop protection and assisting beneficial insects by including flowers in your planting plans. I include a number of tips below which I hope will help you produce healthy crops without the need for too many expensive cures.

Adding manure and seaweedRule no.1 – a healthy soil
If there is any secret to green fingers it is the quality and health of your garden soil. The nutrients released by the life in your soil provide the healthy diet for your plants to thrive and overcome attack from pests and disease. A good soil contains a broad range of nutrients which feed your plants but also strengthen their immune systems. Feeding a chemical based fertilizer is a bit like us surviving on junk food, it is possible but there will be long term impacts with a lot more chemicals required to cope with the inevitable problems it will cause. In short, get your soil right and everything else falls into place.

Getting your soil right basically involves adding organic matter in the form of garden compost, bought in compost, good quality manure, homegrown green manure, fresh seaweed or seaweed meal. There are other amendments depending on soil type but bulky rotted organic material is the most important addition bar none. We can help with all of the above and are constantly expanding our range of the good stuff so let us know how we can help.

Freshly dug maincrop potatoesSowing and planting times
Smart sowing or planting times can also make a big difference when dealing with pests or disease as problems will be more prevalent at certain times of the year. By sowing or planting at the right time we can avoid the worst and produce a healthy crop with far less work on our end. I include a few of the most common tactical growing times below:

Potatoes – The fungal disease Potato blight is pretty much inevitable in late Summer when your maincrop potatoes are maturing. The only way to control blight is to spray regularly with either copper sulphate or a fungicide but if, like me, you prefer your potatoes chemical free you probably won’t want to do this. There are some excellent blight resistant potatoes on the market (Sarpo Mira, Sarpo Axona, Setanta, Orla) which will help slow the disease but you can also grow trouble free tubers by choosing your variety and planting time wisely.

Seed potatoes are split into four categories depending on how long they take to mature; they are first earlies (90 days), second earlies (110 days), maincrop (135 days) and late maincroop (160 days). Potato blight is at its worst in late Summer so if you sow a first or second early variety in mid March you will be ready to harvest by late June/early July and have your crop lifted by the time the disease hits.

Carrot namurCarrots – Carrots can be a little tricky to grow as they are so particular about soil but even if you have the perfect plot you are still likely to be troubled by the very common carrot root fly. The fly lays eggs around your young carrots which produce grubs that burrow into the roots and spoil the crop. The pest can be avoided by growing under a cover of fine insect mesh for the lifetime of the crop but you can also greatly reduce the problem by late sowing.

There are 2 generations of carrot root fly in a year, one in Spring and one in early Autumn. By holding off sowing until mid May/early June you will avoid the Spring generation of the root fly and by harvesting your crop before late August you will avoid the Autumn generation and are far more likely to lift perfect smooth roots.

Pea and bean climbing supportsPeas – Peas are a great beginners crop with big easy to sow seeds and relatively trouble free growth. The two problems you may encounter are pea moths and powdery mildew, I have never had a problem with moths (but they are very common in Southern England) but powdery mildew is very likely in late Summer and early Autumn especially in dry years.

Fast maturing peas varieties sown in March will have a good chance of cropping before the pea moth lays her eggs (the resulting maggots burrow into the peas) but will also avoid powdery mildew as your peas will have finished before the drier days of late Summer and Autumn when the disease takes hold.

Spring cabbage plants Cabbage – The two main issues with growing any member of the cabbage family are cabbage root fly and cabbage white butterfly. The root fly is controlled by covering the crop with mesh or using cabbage collars around the stem of the plant but is not something you can avoid by adjusting your planting times. Cabbage white butterflies are at their worst in late Summer and unless you cover your crop or are vigilant about removing the yellow eggs from the undersides of the leaves you can sustain heavy losses from the hungry caterpillars that emerge.

Pointed Spring cabbage is a delicious treat in Spring when the heads mature from an Autumn sowing the previous August. The plant spends most of its life in a relatively pest free environment as it puts the the initial growth down in Autumn, stands for the winter before maturing in April/May when pests are not around.

Early sowings (indoors, to be planted out later) of cabbage, calabrese, cauliflower, turnip and radish will also mature in late Spring before there are too many pests about.

mini polytunnle garden clochePlant Protection
The introduction of micromesh or enviromesh (they are both the same thing) in recent years has given us a very effective barrier material to keep pests off crops while allowing air, moisture and light to get through. Mesh is a relatively light material that can be simply draped over crops but is best when given some kind of support; this can be a hoop or a frame system that holds the mesh above the foliage of your plants.

Micromesh is effective against a range of pests but is particularly effective against some of those mentioned above, namely cabbage and carrot root fly and cabbage white butterflies. I use it for both and have found it very successful for cabbage root fly where I use our Quickcrop mini tunnels (pictured above) until the plants are properly established. The cabbage root fly maggots will almost certainly kill new seedlings but a more established plant can normally grow through an attack.

Due to the height of crops like flower sprouts, Brussels sprouts and sprouting broccoli mesh is not really suitable for the later stages of growth where protection against the cabbage white fly is required but it is ideal for lower growing brassicas like red and green cabbage.

micromesh crop protection meshA micromesh cover works like a dream on carrots due to their relatively compact foliage which can be safely enclosed from seedling stage right through to harvest. My preference is the ‘Mainframe’ aluminium system as it is light and easy to remove for thinning or for weeding.Remember to do any weeding or thinning in one session and to get the cover back on quickly as the smell of the damaged foliage will attract the fly.

Both the mainframe and the Quickcrop mini tunnels are available on our website as component kits and can be arranged to fit a range of bed shapes and sizes. Both systems can also be used with a choice of coverings depending on you requirements and include mesh, fleece or polythene.

Timber raised bed gardenEncouraging beneficial insects
Keeping your garden ecosystem well balanced will save you a lot of trouble with pests like aphids (greenfly etc…) and hoverfly larvae as other insects will be eating them.

It is worth remembering that pests are always present in any garden but if your beneficial insect populations are healthy they will be keeping numbers down to barely noticeable levels. Predatory insects are encouraged by having a wide selection of plants including flowers and, god forbid, weeds like stinging nettles. If you have room in may be a good idea to ‘cultivate’ a weedy margin to your garden to include nettles etc.. for the important habitat they provide.

I hope this helps!
I hope you find this information helpful and that it gives you the confidence to try natural methods before reaching for a pesticide. We at Quickcrop are committed growing in a way that impacts the environment as little as possible and are always on hand to give any practical help or advice we can. We also stock a broad range of natural plant feeds and pest control products to keep you and your garden happy and healthy. Why not click though to our main shop at the top of the page to see for yourself?

  1. Fionnuala Langford

    Hi Andrew
    Thanks for interesting article.
    Just a thought about carrot root fly.
    When does the spring fly stop being active? I have covered the whole bed with fleece, loosely laid.
    I don’t want to leave it in situ for the whole g owing season. A friend suggested creating a fence around the bed with the fleece instead, arguing that the fly does not go over a barrier.
    Have you any experience with this?

    1. Andrew

      Hi Fionnuala
      Thank you for getting in touch. The carrot fly is not supposed to fly over 2 ft above the ground so a screen of this height is supposed to protect crops. personally I would be a bit dubious as I have grown carrots without protection in 21 inch high raised beds and they were not immune from carrot fly attack. I am pretty sure if I’d gone the extra 3 inches it wouldn’t have made much difference……

      You should be OK from June to August but this is not completely fool proof, personally I keep them covered all the time with a frame but I accept that is easy for me to say as we supply the frames.

      I hope this helps


  2. Dave Anderson

    I realize that having good quality, healthy soil is very important to have a green thumb. Also that it helps protect from insects. My garden has healthy, quality soil in it, but my plants are still getting eaten by those pests. It would be smart for me to call an insect control specialist to get it under control.

    1. Andrew

      Pest control is a wide ranging activity, responding to many different actions of a variety of pests each with their own patterns of behaviour. Understanding the pest is the best start to controlling them.

  3. Kate Caley

    I’m glad that I found this excellent article. I already read so many pieces, but for me, this is the great one. Keep it up to share a helpful article.

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