Is it best to avoid growing sunflowers?

[Z1nn1a]

Read about them being allelopathic . Gardeners World mag has some lovely Red Sun seeds in- tempted but not sure.

Does it reduce the affect slightly if you grow them in a pot instead?

Does it mean they shouldn't be put in home compost after either?

That is very interesting fact and I did not know about it.

laidbackgardener.blog/2017/05/08/when-sunflowers-kill/

Sunflowers rarely make it in my garden for whatever reason, but I have so many other bee friendly flowers in all the seasons so In think imit is fine.

Depends which type of sunflower (effects are not the same between cultivars) and also what else you want to grow nearby.

The studies on sunflowers are at farming level (crop oration, and interaction with immediately following crop).

I'm not sure what if any effect there is in garden level horticulture - can't think of any research.

If you're not sure, then don't have them near important seedlings, and use any compost as a weed suppressant mulch rather than for germination/seedlings

That’s interesting. I always have them randomly popping up in my borders from dropped/blown in the wind bird seed mix and I’ve not noticed anything like this. Must be an at-scale effect as RoseandRose says.

Oh my goodness I didn’t know this. My mil put in loads of massive ones all over my new garden last year! Luckily I did pull them all up and compass them but I’m now wondering if a few casualties are because of the bloody things. Oh no.

blog.gardeningknowhow.com/gardening-pros-cons/sunflower-planting-pros-and-cons/

Haven’t seen Monty grow them. Bit bonkers having them stick on the front of Gardener’s World mag though.

@Svara

Does it mean they shouldn't be put in home compost after either?

The article says they can be composted and decomposition and rain will get rid of the toxins

@DingleyDel

Oh my goodness I didn’t know this. My mil put in loads of massive ones all over my new garden last year! Luckily I did pull them all up and compass them but I’m now wondering if a few casualties are because of the bloody things. Oh no.

The article was suggesting removal and composting as a wayto detoxify the soil, so probably not causing the casualties

I always grow them, in containers with other flowers and at my allotment and have never noticed them effecting other crops. They're really popular to grow on the allotment, lots of people try to grow the tallest one so they grow lots of them and then compost them. From what I understand about alleopathy it's very specific, so the hedge mustard is alleopathic towards other hedge mustards but not other plants in general. I think the research suggests if you've planted a field of them when you rotate the crops certain crops may not germinate as well after sunflowers, on the other hand you'll also have less weeds so they can be beneficial in that way. They also attract lots of pollinators so will increase yields of other crops, so it my balance out. It wouldn't put me off growing them at all. I don't tend to plant seeds directly anyway, it doesn't seem to affect plants that are already growing.

A less sensationalist view of the topic: en.m.wikipedia.org/wiki/Allelopathy

I've grown some behind other annuals for the last couple of years and haven't noticed any issues with the other plants growing. They attract blue tits who show up in the morning and late afternoon to eat the seeds which is what I hoped would happen. They happily peck away just a couple of metres from our seating area. Might be less endearing if you're growing for cutting.

They don't do any permanent damage. MereDint is right.

If you pay attention to your sunflowers this year, there will be a little clear space around the base of it. This is noticeable if it's included in a so-called wildflower or wildlife mix- all the others wille growing on top of one another in an untidy fashion, but the sunflower will carve out it's own little space.

I always make room for them. I love them and DC enjoy watching them grow and then tower over them.

There are other things, esp veg like cabbages and peas, that I am far more loath to grow as they really do seem to exhaust the soil

There are other things, esp veg like cabbages and peas, that I am far more loath to grow as they really do seem to exhaust the soil in theory peas should be OK. As legumes, they develop nodules on their roots full of bacteria capable of fixing nitrogen from the air. Wasn’t the sequencing of crops in a rotation all about this? - cabbages as heavy feeders, legumes capable of fixing nitrogen, their roots left to break down in the soil to restore nutrient levels.

Your experience will be better thine mine, because I grow veg in containers, changing the soil between crops, so I don't have to worry about crop rotation

They are very good for bees immune systems so please keep planting sunflowers.

Grow them because they will bring you joy.

I never knew this, I'm struggling to think that we've noticed any effects.

Too much hassle to harvest the seeds at the end, but we enjoy having the flower heads in garden, otherwise.

I never knew this either, but have happily grwon sunflowers in my front garden borders amongst many other flowers before, so will continue to do so!