Can I raise garden bed without transplanting perennials?

11 years ago

Hi all,

I'm hoping to raise up my garden this coming spring. We have really compacted clay soil and poor drainage. I was thinking of raising the whole thing up 6-12" and add a mix of peat moss, top soil, and compost.

We have some perennial flowers and herbs in there though. Do I need to transplant these out and back into the garden or would they do fine coming through the extra soil? We have kale, a common sage the size of a small bush, tarragon, and thyme. The flowers are a shrub rose, a day lily, some black-eyed susans, sedum, and three balloon flowers.

Mostly, I'm worried about the balloon flowers, since they've been there for 10 years and are really well established. I've always heard they're next to impossible to transplant.

Thanks.

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Comments (5)

ken_adrian Adrian MI cold Z5
11 years ago
yes you must ... nothing is going to grow up thru 12 inches of soil ...

first.. if you want 12 inches.. think about adding 15.. so that when it settles ...you actually have 12 .. much more important.. at the lower end.. if you want 6.. and put 6.. you might end up with 3 ...

next .... take out the plants on one side ... improve that area .. jam the plants back in ASAP ... close together ... simply to HOLD THEM OVER...

remove other half to the new area.. still jammin ... lol ... do second half ...

then anytime next summer.. start moving them around ...

with this method ... you can make it a 2 weekend project.. it just gives you alternatives to killing yourself on a none day project ... ... presuming this isnt checkbook gardening ... and you will have a 10 man crew out there ...

the VERY MOST IMPORTANT VARIABLE... will be tracking down.. and securing GOOD SOIL ... this is not simply going to be calling the closest place.. and ordering up a truck full ...

you want to find a good peat based soil ... with some amount of sand for drainage.. perhaps a new post.. if you wish to discuss soil science ...

so pay up front for good stuff.. and you will be rewarded ...

now ... the real question.. is 12 inches enough ... for high compact clay ... if you are hoping to garden COMPLETELY on top of the clay ... you might want to consider 18 to 24 inches ... i do NOT know ...

but the one thing i do know.. DO IT RIGHT THE FIRST TIME... there have been too many garden projects in my life.. that i finally won.. THE THIRD TIME I REDID IT.. lol

good luck ...

ken ...
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flora_uk
11 years ago
Fill in the missing words in these well-known sayings ;-)

'If a job's worth doing, it's worth doing .......'

Alternatively:

'It's a pity to ...... the ship for a ha'p'orth of tar.' (Where 'tar' = effort)

You really need to bite the bullet and remove all the plants. If you dig them out with enough soil around the roots they should be OK. (The kale BTW will be over by next summer anyway). The herbs, especially, would hate having their crowns covered in 6 inches of stuff, although the sage might be OK if it is really a small bush ie about 3 feet tall and wide.

I'd remove the plants then fork up the base of the bed to improve the drainage and break up the clay a bit. Then add your new materials. Then replant the plants.
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Missti - Your questions really aren't silly - we all started where you are and learned from other gardeners. My husband always says (quoting his mom) that the only dumb question is the one you didn't ask! Organics will be material largely from plants - leaves, manure (since much of the celulose in plants goes through the digestive system of horses, cows, etc without too much change), grass clippings, coffee grounds, etc. You can get bagged organics at garden supply places, but you may also have bulk local sources that may be free (if you are willing to load and haul yourself,) or inexpensive. I've heard of folks who live in cities asking the local coffee place if they can pick up their used coffee grounds. Around here we get a mix of sawdust (used for horse bedding) and horse manure from one of our neighbors who has horses, or the local dairy farm will deliver a huge truckload of fresh manure (which your neighbors might not appreciate if you have an in-town lot!) The next town over has a municipal composting program; they collect leaves and grass clippings and such, compost it, and offer it free or inexpensively for residents if you come to their storage area with a pickup truck or large containers like garbage cans. The local power company hires someone to cut and chip branches that are endangering lines, and we have found that the tree guys will usually drop off a load or two or five if we ask nicely and no one else has asked first. I also can get wet sawdust from the local sawmill or wood shavings from a shop. Any of these can be mixed into your local soil to add organics and improve your soil texture. If you use uncomposted materials like wood chips, sawdust, or wood shavings you need to add a reasonable amount of nitrogen, mixed into the soil as well, since the process of decompsition uses nitrogen and your plants will end up suffering from too little available nitrogen for their own growth. (Some people say never to use wood chip type materials, but I've been doing it for years successfully. You just need to be sure to avoid walnut wood products and add lots of nitrogen.) For future use you can also make your own compost from your own leaves and grass clippings as well as kitchen scraps of any plant-based material and add it to the top of your soil - over time the worms and burrowing mammals like voles and chipmunks will mix it in for you as long as you keep adding it to the surface. For information on how to do composting, check out the FAQ on the soil, compost and mulch forum. Here is a link that might be useful: soil, compost and mulch forum
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Karen, I'm glad to hear that you also have the inclination that adding mineral soil is the right answer. When creating the beds, I wanted to add good soil with lots of organic matter, and I also wanted to avoid spending a fortune on it. The topsoil/peat/manure mix was good for that, and it's been an absolutely fabulous growing medium with excellent water-holding capacity but also excellent drainage, but overall was probably too high in the organic matter for long-term stability. It's also possible that the heavy rains earlier this year contributed to the higher rates of decomposition and therefore more shrinkage. I will say that I'm not looking forward to digging up and replanting all of those plants, plus all of the additions to the bed, yet again. The herbs are even bigger, being a year older, and even last year they had larger root systems than I ever would have imagined. Some are due for dividing, which is fine, but leaving the others exactly where they are would have suited me. Maybe I can get by another year with the current levels, and only moderate topping-up.
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mistascott
11 years ago
You will essentially be burying the plant crowns and subjecting them to rot. Also, if somehow they didn't rot, they may not have the energy to get through that much soil. Therefore, I think many would perish. I would transplant them in Spring. Balloon flowers can be moved, but you have to be sure you dig a very wide and deep hole and really get those roots.

Raising a bed is generally a good solution for poor drainage, but if the drainage is especially bad, it may not solve the problem as the water could back up at the clay line and saturate your raised bed as well. I would suggest trying to amend the exisiting soil with compost. However, to really amend the soil well, you have to temporarily remove the plants -- so you might as well raise the bed if you are going to all that trouble. I would really work the compost into the existing clay 6"-12" or so deep to try to improve the drainage before adding the soil for the raised bed.

Also, I wouldn't use peat moss as a soil amendment because it retains moisture (when you want the opposite), it steals nitrogen from the surrounding soil as it decomposes, and doesn't add nutrients to the soil. Top soil is also troublesome because its content is not regulated so you have no idea what you are getting. It is good for filling in large holes and raising a garden bed, but I would mix it with a pretty heavy dose of compost (no less than 1/3). See the below link for more information.

Here is a link that might be useful: Improving Your Soil
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CaraRose
Original Author
11 years ago
Thanks everyone.

My mom planted the balloon flowers so I'll need to see if she's okay with me trying to transplant them. Otherwise maybe I'll try a smaller raised bed towards the back where we have open space without any of the perennials that I don't want to risk killing.

Last year I worked the soil open parts of the soil 4-5 inches with a rototiller. Then added compost and top soil and worked that in. Maybe it just wasn't enough, but the soil compacted back down again. I tried some root crops this year but none of them seemed able to grow well in that soil.

I had some success with my raised bramble bed using 1/3 peat, 1/3 top soil, and 1/3 compost. But those like acidic peaty soil.

--The kale BTW will be over by next summer anyway--

It's already 5 years old and a 3' high monster. I had to hack it back a ton earlier this year because it was crowding out the tarragon. I think it's a type of Blue Scotch. Tasty, but grows like mad.
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CaraRose
Original Author
11 years ago
Interesting on the kale, I was curious and googled and saw most varieties are bi-annual. This one is definitely perennial. It was labeled blue scotch, but I have my doubts on that now. It has self-seeded other plants, but the original two were there for five years if not more (I dug up all but this last one to make room last year).
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Can I raise garden bed without transplanting perennials?

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ken_adrian Adrian MI cold Z5

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Can I raise garden bed without transplanting perennials?

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ken_adrian Adrian MI cold Z5

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