Aster in clay soil?

Mariam_86

I have two aster plants in pots. They are quite demanding plants and I’d rather plant them in the ground. The soil in the garden is heavy clay, the greyish type but which turns reddish when digging deep. It gets waterlogged when it rains heavily.

Will asters do well in these conditions?

It may be helpful to know that hebes have not done well in the same area I want to plant the asters. Hydrangea have done ok. 

Fairygirl

No, is the short answer. Very different from Hydrangeas in their requirements - as are Hebes. 
The drainage is the big factor for asters and hebes. You'd need to spend some time adding lots of organic matter to break up the clay. I built raised beds to counteract the clay here, and enable me to grow plants which wouldn't appreciate it. The bed which wasn't raised, and was created from a compacted grassed area, had loads of manure added, and I was able to plant it up the following spring. It's still a heavier medium than the raised beds, despite lots of compost added regularly

Alan Clark2 in Liverpool

I have clay soil and asters do very well here. I don't know how my clay compares with your clay, so you might need to improve yours, but it should not need much improvement for your asters to succeed.

Loxley

Yes - if you improve the soil as FG outlines. If you don't want to do raised beds you could make the border into a berm (a gentle linear mound, highest in the middle), incorporating free draining material and organic matter to raise the level, breaking up any compacted clay underneath as well.

Pete.8

I agree that asters will not thrive if planted in thick clay (and nor will much else), but I have Essex clay that I've improved over the years and asters thrive here

Mariam_86

Thanks all. I have improved the soil by adding soil improver and some composted manure. I did this in the spring. It’s still very heavy and waterlogged when raining. I think it will take years to see substantial improvement. 

@Loxley thanks for this suggestion. From what your suggesting, I understand I should add top soil and composted manure as a mound and then plant on that? How high are we talking? 20cm?

@Pete.8 asters look great! 

Mariam_86

@Alan Clark2 in Liverpool good to hear this. That’s encouraging. Hopefully my asters won’t have the same fate as my hebes. 

Fairygirl

It can take a long time to get it into a suitable medium for asters, and other plants which like similar conditions. I do grow them, but in the raised beds. I can't control what falls out of the sky, or the temperatures in winter, but I can mitigate it by creating a decent soil for them to [hopefully] thrive 
I knew I was on a hiding to nothing when I moved in here, trying to create borders in what was just a car park. Paving, gravel and compacted clay. It was always going to be easier to create raised beds, and I've got previous experience of doing it, so it wasn't a problem for me 

Loxley

I would say 20cm is enough, you'll work organic matter into the upper layers of the existing soil as well. Don't be tempted to add grit in the deeper layers - any voids will just fill with water - but it can be helpful worked into the surface layers. Norwell Nurseries have a heavy clay soil and specialise in asters, but they really have worked at the soil over the years. If it's just one border in a typical garden, things are more manageable.

Mariam_86

Fairygirl said:

It can take a long time to get it into a suitable medium for asters, and other plants which like similar conditions. I do grow them, but in the raised beds. I can't control what falls out of the sky, or the temperatures in winter, but I can mitigate it by creating a decent soil for them to [hopefully] thrive 
I knew I was on a hiding to nothing when I moved in here, trying to create borders in what was just a car park. Paving, gravel and compacted clay. It was always going to be easier to create raised beds, and I've got previous experience of doing it, so it wasn't a problem for me 

Glad it worked out for you! 

It’s my parents garden that I garden on, so I’m keen to just improve the garden as it is, rather than make big changes like raised beds.  Although not a car park, it may as well have been, since the ground has probably never been dug over as it was all grass/weeds.

Mariam_86

@Loxley thank you.

Will try this. Yes it’s a medium sized typical garden and shouldn’t take long to do what you suggest.