Some professional advice
Category: Tips
Allium Leaf Miner
Allium leaf miners are the larva(maggots) of a little fly that lays its eggs on the leaves of our alliums (onions, shallots, garlic, leeks, etc). The larvae hatch out and tunnel down, eating and growing as they go, then pupate in the bulb area. Their damage causes the plants to become distorted, and opens them up to fungal disease. There are some good pictures to help identify them on these two web pages:
The RHS have some useful advice about how to cope, as does Garden Organic (members only, unfortunately). There is no cure – only prevention, which means destroying infected plants to kill the larvae and pupae, and keeping the flies from laying their eggs on our crops by covering them with nets. The flies are quite small, and the RHS advise using very fine mesh (0.8mm) netting, as the standard “fine” mesh (1.3mm) is not reliable.
The adult flies are active in early spring (March + April) and again in the autumn (October + November), which is when you need to cover your crops. These dates are a bit uncertain, as the pest is new here and we are still learning about it.
Borlotti Beans
I struggle to find things that work on my plot, but French beans and recently, Borlotti beans are my favourite…

Rats, Squirrels Eating Sweet Corn
I noticed about that squirrels (probably) were starting to eat my ripening sweetcorn …
Potato Blight
Some time in August, especially when the weather is warm and damp, our potatoes plants start showing signs of blight.
Peat Free Composts
A report by Rosie Hall for Hollin Lane Allotment Association
A report by Rosie Hall for Hollin Lane Allotment Association
Background
Peat only started to be used in garden composts in the 1950s with the rise of popular gardening. Humans have used peat for centuries as a fuel, a building material, for animal bedding and, more recently, for horticulture. In the UK, gardeners and commercial growers get through 3.5 million cubic metres of peat a year. To meet this demand, areas of lowland bog are being stripped of their peat, destroying valuable habitats both here and abroad (65% of our peat is now imported). Because peat bogs take so long to form they are an unsustainable resource. If we continue to destroy these peat habitats we will ruin a vital part of our natural heritage, lose many rare plants and animals, and valuable information about our planet’s past.
While some of our remaining peatlands are protected, there are many in other European countries that aren’t, and it is these which now supply most of our garden peat.
Peat in the garden
Peat has three uses in the garden: as mulch, as a soil improver and as a growing medium.
- Mulches
- A mulch is a layer of material spread on top of the soil to keep down weeds, conserve moisture and insulate the earth. Peat-based mulches do a relatively poor job as they break down quickly in dry conditions and often just blow away. Better mulches are based on bark, leaf mould, recycled wood waste, spent mushroom compost or garden compost.
- Soil improvers
- Peat adds no nutrition to the soil. Better products for this are manure, compost, spent mushroom compost (though this is of variable nutritive value)
- Growing media
- All growing media should be peat free by 2020 according to Government targets. Growing media do not have to be based on Peat. They can have the following as a basis: composted bark, coir, leaf mould, garden compost, screened green waste and screened composted manure
Peat-free Products
Clearly we need different grades of media for different jobs in the garden; the differences in water retention are also very important.
In researching the available peat free products it is clear that one product will not fit all. Multipurpose works all right up to a point, but often the products are far too coarse for seed sowing. In looking at available products I have tried to take the following into account, but there are sure to be other factors- it is a huge task!
- Have the products been tested by reputable trials?
- Are products available locally? How much do they cost?
- Do we know what the products contain?
- Are the companies involved in production of peat-containing products? I added this as something we might like to consider.
- Have the products been tested by reputable trials? The Royal Horticultural Society has some useful pages on peat free gardening. The main points for my purposes were:
- In their trials they found that there was very little information on the main components of the composts.
- They found considerable variations in quality between batches.
- The more expensive composts tended to perform better.
- Water management is critical.
- How best to feed was a subject for further research.
Other trials:
Which? Test scores for 2010 as a percentage of germination in the following peat free composts:- New Horizon Multi-Purpose: 80% (also top in 2011)
- Westland Multi-Purpose: 80%
- J Arthur Bowers Multi: 74%
- Levington Multi: 74%
- Vital Earth Multi: 74%
- Murphy Multi: 73%
- Vital Earth Tub/Basket: 70%
- New Horizon Growbag: 65%
- Shamrock Multi: 63%
- B&Q Tub/Basket: 53%
- J Arthur Bowers JI no. 3: 50%
- B&Q Multi: 49%
- Westland Earth Matters: 48%
- B&Q Peat-Free Multi: 46%
- Westland Multi: 43%
- Westland Container/Basket: 39%
- Miracle Gro Peat-Free: 28%
The previous Which? Score put B&Q multipurpose and New Horizon organic and peat free growbag along with B&Q sowing and cutting compost as top 3 for sowing composts. They suggested that Homebase multipurpose and Vital Earth were not worth buying as the germination was< 40%. (Compare with results above)
A report in The Ecologist suggested that Petersfield and New Horizon both scored 90% germination.
The trials are difficult to interpret. They do seem to illustrate that there is sufficient variation between batches to lead to variable germination rates, all else being equal. - Are products available locally? How much do they cost?
- New Horizon Multipurpose Peat Free is widely available; High Trees would deliver any amount for £18; a bag costs £5.99. Garden Goodies (Bingley) would deliver eg 30 x 60 litre bags for £186+VAT including delivery.
- Moorland Gold (see below) from West Riding Organics priced as follows: 20-64 x 40 litre sacks £5.34 each (individual price £7.99), full pallet £4.79 each (max 65 sacks) delivery £42 + VAT
- Knotford Nook (Lancashire) bulk loads up to 5 tons (£40/ton -£60/ton depending on whether screen size and whether manure based)equivalent to a builder’s 1 cubic metre sack) £40 delivery + VAT
- Petersfield which received good reviews, is based in Leicester so is not considered further here.
- These are the ones I enquired about as a ‘taster’. Most on the Which? list are available locally.
- Do we know what the products contain?
- New Horizon Peat Free: bark, timber residues, green waste, limestone, hoof and horn, rock potash, Vinasse (?) bone meal. Will need more watering then peat, and extra feeding after 4-6 weeks.
- Moorland Gold: This is not peat free, being made of a mixture of entrapped peat from water purification + sharp sand. It is therefore a by product using a waste material, so not reliant on peat extraction. It is Soil Association Certified.
- Knotford Nook: There are various types based on either green waste, mature compost or farmyard manure. They are screened to 40/30/20/8 mm, so suitable for different purposes.
- Are the companies involved in the production of peat containing composts?
- New Horizon makes peat-containing composts. Since all compost will have to be peat free by 2020, this is going to change the picture considerably.
Conclusions
- It would be good to encourage the use of peat free composts on the allotment site.
- We should invite comments on this report from the plot holders.
- We should consider buying a bulk load of compost or a couple of bags of several types to do our own trial.
- Making our own means allocating an area , collecting leaf mould etc
- We should make sure that every plot holder is helped to produce garden compost for use in mulching, soil improving and as a growing medium.
- We should try to make Hollin Lane Peat Free as soon as possible
Making Compost
Here are the slides from the talk on Making Compost from the 2011 AGM.
Pea and Bean Weevil
The pea and bean weevil is hard to spot, but its damage to peas and beans is easy to see …
The pea and bean weevil is a horrible little creature called Sitona lineatus. It is quite small (5mm) and hard to spot, but its damage to peas and beans is easy to see: neat half-round notches cut out of the edges of the leaves of young plants.
They overwinter in the soil near peas and beans (and winter tares), and come out in warm weather. They lay lots of eggs on the host plant during May, June and July, and the tiny larvae then find their way into the soil and feed on the roots. They are annoying, but don’t usually cause serious damage. The best advice seems to be to keep the young plants well fed so they can outgrow the danger, as the weevils don’t climb very high. Rotating your crops helps, too.
Joe Foster
Good Varieties for Hollin Lane
Here are some vegetable varieties that do well here. Please give us your own favourites with a few words saying why you like them.
Vegetable | Variety | Qualities | Author |
---|---|---|---|
Cabbage | Greyhound | Tasty and trouble-free cabbage for early summer | Peter Byass |
Cabbage | Marner White Storing | Huge dense round heads that stand well through the winter | Peter Byass |
Kale | Nero di Toscana | Fairly hardy - delicious dark green leaves late summer and autumn | Joe Foster |
Kale | Pentland Brig | Very hardy - pick leaves in autumn and winter and sprouting shoots in spring | Joe Foster |
Onion | Centurion | Round, good cropper, keeps well in store | Peter Copeland |
Potato | Charlotte | 2nd early, ready before blight and slugs hit, salad type | Joe Foster |
Potato | Colleen | 1st early, yellow flesh, good baker, good blight resistance. | Jayne Harnett |
Potato | Jazzy | 2nd early, ready before blight and slugs hit, salad type. Better eelworm resistance than Charlotte | Joe Foster |
Potato | Harmony | 2nd early, some blight resistance | Jenny Ward |
Potato | Kestrel | 2nd early, ready before blight and slugs hit, delicious baked or mashed and a good cropper | Joe Foster |
Potato | Nadine | 2nd early, some blight resistance | Jenny Ward |
Potato | Nicola | Early main crop, salad variety, some blight resistance | Jenny Ward |
Potato | Record | Main crop, floury, some blight resistance | Jenny Ward |
Potato | Remarka | Early main crop, some blight resistance | Jenny Ward |
Potato | Sante | Main crop, some blight resistance | Jenny Ward |
Potato | Sarpo Axona | Late, good blight and slug resistance, good cropper and keeper | Joe Foster |
Potato | Sarpo Mira | Late, good blight and slug resistance, good cropper and keeper | Joe Foster |
Not So Good Varieties for Hollin Lane
Some fruit and vegetable varieties just don’t work here. Please give us your own experience with a few words about what the problem was.
Vegetable | Variety | Qualities | Author |
---|---|---|---|
Potato | Marfona | 2nd early. The slugs love it. | Joe Foster |
Cabbage | Hispi | Not very tasty. Attractive to slugs. | Peter Byass |
Brussels Sprout | Evesham Special | The sprouts are mostly blown – hardly any solid ones. | Joe Foster |
Onion | Golden Bear | NOT tolerant of downy mildew! | Joe Foster |