Isolation Garden

[honeydew]

The hubby emphatically agreed today that he will make me a new garden ready for next June - GASP!

Anyways, the site should make a great little sunny microclimate, with trees to the north and west, a give or take 10 foot cutline and then more trees. To the south is a farm road next to a fence with a very recently cleared treed area on the other side. It is currently triangular in shape, bordering brush, which he said he would like to clear to make square, which would make it to be about 40 x 40 or larger. Currently populated with grassy type stuff and loads of goldenrod.

It is situated at least about (I haven't measured) 700 - 900 feet from the north border of the main garden. There are lots of trees in between.

Is this enough isolation to plant one of each outbreeding veggie? Corn, c. pepo, c. moschata, c. melo c. maxima, runner beans, sunflower and on and on... just was thinking it would make it soooo much easier to save seeds when growing multiple varieties.

We have bees on the other side of the main garden, which is 250 feet from one side to the other.

TIA
Marie

[Joseph Lofthouse]

It sounds like the trees are very close to the garden... I get poor results whenever I plant garden vegetables within 50 feet of a tree. I guess the tree roots suck away the moisture and nutrients from the garden vegetables.

Last year in my garden a separation distance of 85 feet resulted in about 1 foreign corn pollen per 500 kernels of corn. I didn't notice any foreign pollen this year in patches that were planted 120 feet apart and 140 feet apart. (I looked for it.)

I would be thrilled with an isolation distance of 800 feet.

[honeydew]

That's the problem with living in the forest. Trees everywhere! This new garden is by trees, but in the closest vicinity is newer saplings that have been allowed to grow in, if that even makes a difference.

How do you tell if there was foreign pollen? Did you have any tall plants separating as well as distance?

[MikeM]

Nov 29, 2010 0:57:39 GMT -5 Joseph Lofthouse said:

It sounds like the trees are very close to the garden... I get poor results whenever I plant garden vegetables within 50 feet of a tree. I guess the tree roots suck away the moisture and nutrients from the garden vegetables.

Same experience here. The southernmost part of my veggie beds ended up too close to the treeline on the boundary of my property, and a good 1/3 of the bes were pretty useless - soil dry, powdery and lacking in everything. I'm guessing, but suspect that the trees (Acacia melanoxylon - Australian Blackwoods) might also have some root exudate that discourages or posins other species.

Anyway, I cut a trench about 30cm deep between the trees and the veggie beds, severing many of the tree roots (and, not incidentally, the Kikuyu grass!) and there's been a marked improvement. I plan to deepen that trench and eliminate the trees in that part of the garden in favour of some less aggressive tree species. The trench seems to have made the most difference, though...

All I need now is a few tonnes of compost to improve the soil in the beds...

[honeydew]

I'm guessing my husband will use the deep tiller and disc several times until it is good and broken up. The deep tiller gets a bunch of the tree roots and drags them out.

Will this make it okay?

[paquebot]

Dec 21, 2010 0:38:30 GMT -5 honeydew said:

I'm guessing my husband will use the deep tiller and disc several times until it is good and broken up. The deep tiller gets a bunch of the tree roots and drags them out.

Will this make it okay?

No! Roots aren't usually much beyond the drip line. If the trees are so close that there will be roots tilled up, you are too close to the trees. The roots will regenerate before the summer is over and quite probably seriously affect the harvest.

Martin

[honeydew]

I have found that poplar roots go really far......we have poplar about 25 feet (too close I know, we are working it back) from the north side of the greenhouse, and there were roots sending up suckers IN the greenhouse! I had to get the hubby to take the deep tiller in there this fall, and he dragged out a bunch or roots! We periodically drag the deep tiller behind the greenhouse to catch new ones growing out.

So, for this isolation garden, perhaps the best course of action is to clear the trees to the north some more, and leave a buffer to deep till next to the treeline? Say 20 feet? There are a lot of polar saplings there that would be very easy to remove, then it is a mix of more mature poplar and spruce.

I know nothing grows too close to the spruce (ask me how I know!), but I think it's from the needles that drop to the ground more than anything???

[tgardenator]

I've heard the needles in the soil around evergreens result in acidic soil. Maybe a neutralizing soil amendment would help? Maybe a little hardwood ash and lime? (not too much though)

[mjc]

Pine needles are not a significant source of acid, not enough to actually acidify anything than the top fraction of an inch of soil, if that. The acids contained and produced by pine needles also breakdown quickly.

What is more significant, that pine needles contain, are terpenes. Terpenes can prohibit germination of seeds, but have little or no effect on already growing plants. The terpenes are not very long lasting, either, so if the pine needles compost for a few weeks/months they will have mostly dissipated or have broken down. Continually adding more pine needles, as would occur under a living pine tree keeps up the supply.

This is why, most pines will not germinate under the 'mother' tree...and clear-cutting/fire is needed to get them to germinate. It's the pines' (and related spruces, firs and most other conifers) natural competition suppression method. Clear-cutting removes the source of fresh needles, while fire quickly cooks off residual terpenes (think of the volatility of turpentine...you'll get the idea). After a clear-cut and a season sitting, if erosion control measures are taken, there will be thousands of pine seedlings germinating...the same after a fire, but if it is early enough in the year you can get large numbers sprouting before autumn sets in.

Another very significant problem, under conifers, is the change in soil texture that occurs, due to the lack of water. It tends to become dry and fluffy and very difficult to wet, kind of like dry peat moss. This is because conifers are very good at directing water to where it will do the most good...along the drip line. Because of this the soil underneath slowly becomes very dry. The best cure for this, from a gardening standpoint, is to remove the tree or at least many of the lower branches and mulch heavily for at least an autumn and winter...a full year would be even better.