Onions

[Containergardener]

Lately I have just concentrated on spring onions since making a couple of beds.
One bed has mostly been spring onions and salads, chard etc. The other has been peas and beans.
I know ideally I'd have another bed to alternate better which I can still do and debating on.

Question is I read don't follow onions with peas etc , I'm happy for peas to stay in that bed but should I not put onions back in the salad bed because of the previous onion, onion problems?
I'm hoping for red onions, leeks and spring onions this year.

Of course I could always use containers.

[mothhawk]

I think this is a nitrogen problem, isn't it? Too much nitrogen is not good for onions. I can't see the peas would be a problem if you pulled up all the roots when you cleared the bed (thus removing the nitrogen fixing nodules on the pea roots), and the bed has been exposed to the weather over the autumn/winter, as rain will leach out some more of the nitrogen.

But I don't grow onions, so I'm sure someone will be along with better knowledge.

[rary]

What onion problems have you had previously, though if in doubt I would go for containers, with using containers, onions can be planted closer together as you can hand weed easier

[Containergardener]

None rary I've only had the bed a year. Just reading you shouldn't follow onion with onion . Or pea after onion.

[rary]

Sorry CG I read that wrong I thought you had an onion problem in your soil, but you should know I have grown onions in the same bed for a couple of years several times in the past, and will be growing in the same bed again this year, I know several gardeners who have grown in the same bed for three years, if you are short of space then you can grow in the same ground for about four years, you of course need to apply a suitable feed such as chicken pellets for a high nitrogen at the start, followed by a balanced feed once the bulb forms, my onion bed has been covered with seaweed and I will spread some chicken manure a couple of week before planting out my onions, and a wee tip for you if you ever get white rot in your onion bed, apparently you can buy garlic pellets for horses, so if you can obtain them, scatter them over your bed just as the soil starts to heat up, this will get the virus activated and as there is nothing for them to feed on they die off, clearing the bed of white rot, if you cant get the pellets, you can steep garlic and onion skins then soak the ground with that once a week for a month

[KJessi]

So informative, thanks.

I've been wondering why my onions and leeks don't ever do well for long. So it's too much nitrogen and a failure to fertilise properly. I use comfrey/nettle tea, with tomato feed for fruiting things. That's it.

I actually use dry onion and garlic powder in the kitchen. I'm assuming we can use that to mix up a white rot soak too?

[Containergardener]

Thanks Rary you are a star. I've some fresh compost to load on too. Will grow in the same bed again.

[rary]

So informative, thanks.

I've been wondering why my onions and leeks don't ever do well for long. So it's too much nitrogen and a failure to fertilise properly. I use comfrey/nettle tea, with tomato feed for fruiting things. That's it.

I actually use dry onion and garlic powder in the kitchen. I'm assuming we can use that to mix up a white rot soak too?

With powder I would just dust it over the soil, I am not an expert but think the reason for using pellets is that it gives off a chemical signal but as there are no roots for the virus to cling to and feed off it dies off, it would be a lot more economical to let garlic soak in water then water the ground with that
As for your feed, I would give the onions a feed with nettle tea till they start forming a bulb then switch to the comfrey, or tomato feed and only apply it once a week at the most, too much feeding is just as bad as not enough,

[Andraste]

Interesting topic CG.

I've always gone on the theory of rotation to avoid risk of disease/pests building up if growing the same thing repetitively in the same place, but there are plenty of the old guard on our site that have never rotated without issue.

It's always good to feed your soil whether rotating or not, but if you're not rotating then the nutrients specifically needed by the plant you're growing will become depleted over time so it becomes even more important if you want good yields etc. (hence plants are put into groups e.g. brassicas for rotation so they all have roughly the same needs & can potentially achieve benefit from the earlier crop e.g. roots following spuds works nicely because spuds break up the ground).

I googled why you shouldn't plant beans after onions as I was interested to see if there was a reason specifically and the AI feature said "Planting beans after or near onions is generally discouraged because onions produce antibacterial compounds, such as allicin, that can inhibit the beneficial bacteria (urease) needed by bean roots to fix nitrogen, resulting in stunted growth and weaker, lower-yielding crops."

[Containergardener]

That's what I read too Andraste re the inhibiting growth etc.

[Vince G]

Peas and beans follow alliums in my rotation, have never not got a good pea or French bean crop

[Containergardener]

Thanks Vince. Always better to get others experience than reading it elsewhere.

[burnie]

I never plant anything in the same ground two years running, I use a three year cycle including in the greenhouse. I use farmyard manure before planting onions and tatties follow them the year after, so far no problems, I now only grow peas in my greenhouse, I seem to get an earlier and better crop. Broad beans then follow from tatties, works for me.

[Vince G]

I'm the same Burnie, rotation is so important. I'm lucky enough to have 1½ allotments so I've got 6 designated plots (as follows for this year):

1. Legumes Peas and beans
2. Alliums
3. Spuds
4. Umbellifers
5. Miscellaneous which is mostly squah, courgettes, pumpkin, sweetcorn
6. Brassicas

Next year 6. goes to the top and everything drops down one.

I think it's important for brassicas to follow legumes, because not only will I have mucked the legume bed, but they fix nitrogen which is required for green leafy growth.

I also think it's important for the umbellifers to follow my miscellanous bed. This is because the miscellaneous is sparseley mucked, which makes it good for the roots the following year. Although having said that, some of you might have seen my mosnter parsnip post, which was most likely caused by planting parsnip seeds on a pocket of manure I planted a courgette in the previous year, so anomalies can occur.

The rest of my rotation is not so much concerned with soil condition as with correct timing of the availability of the land. For instance the spud bed is clear by the end of October so next year's autumn sowing alliums can go in. Miscellaneous group are generally not planted out until May, but they follow brassicas and we're usually still using up the last of the late caulis and white sprouting broccoli in early spring.

Nature is pretty amazing isn't it where one crop provides for the following one.

Also got 3 other small beds where I grow salads, sweet potatoes and the last is for spares if I run out of room in a bed.

burnie I'm interested in your greenhouse rotation. I've got a 10x10 poly with 2 beds either side of the front to back door path. I grow Toms and basil on one bed, and peppers, chillies, aubergines and melons the other side. These are mostly all the same family so whilst I swap each group from side to side each year, I usually just end up digging out and replacing all the soil every 5 years as I think proper rotation and soil maintenance is a bit tricky. Any suggestions appreciated. Interested by your greenhouse peas too, whereabouts are you and when are you harvesting them?

[burnie]

I'm the same Burnie, rotation is so important. I'm lucky enough to have 1½ allotments so I've got 6 designated plots (as follows for this year):

1. Legumes Peas and beans
2. Alliums
3. Spuds
4. Umbellifers
5. Miscellaneous which is mostly squah, courgettes, pumpkin, sweetcorn
6. Brassicas

Next year 6. goes to the top and everything drops down one.

I think it's important for brassicas to follow legumes, because not only will I have mucked the legume bed, but they fix nitrogen which is required for green leafy growth.

I also think it's important for the umbellifers to follow my miscellanous bed. This is because the miscellaneous is sparseley mucked, which makes it good for the roots the following year. Although having said that, some of you might have seen my mosnter parsnip post, which was most likely caused by planting parsnip seeds on a pocket of manure I planted a courgette in the previous year, so anomalies can occur.

The rest of my rotation is not so much concerned with soil condition as with correct timing of the availability of the land. For instance the spud bed is clear by the end of October so next year's autumn sowing alliums can go in. Miscellaneous group are generally not planted out until May, but they follow brassicas and we're usually still using up the last of the late caulis and white sprouting broccoli in early spring.

Nature is pretty amazing isn't it where one crop provides for the following one.

Also got 3 other small beds where I grow salads, sweet potatoes and the last is for spares if I run out of room in a bed.

burnie I'm interested in your greenhouse rotation. I've got a 10x10 poly with 2 beds either side of the front to back door path. I grow Toms and basil on one bed, and peppers, chillies, aubergines and melons the other side. These are mostly all the same family so whilst I swap each group from side to side each year, I usually just end up digging out and replacing all the soil every 5 years as I think proper rotation and soil maintenance is a bit tricky. Any suggestions appreciated. Interested by your greenhouse peas too, whereabouts are you and when are you harvesting them?

Here you go, a video I did a couple of years back, explains the crop rotation, I'll find the one with the peas later.
https://youtu.be/TB7hZ98Hdyw