[permaculture] The Effect of Cultivars on Native Species Gene Pools

dwoodard at becon.org dwoodard at becon.org
Wed Dec 30 18:00:01 EST 2009

I think a lot depends on the state of the native population. For species
like the hickories and black walnut in southern Ontario, I don't think
there is too much of a problem, especially if one plants the cultivars or
selected seedlings near the dwelling and not mixed with native
populations. It's true that bees can fly up to two miles, but they prefer
not to.

Most of the nut tree cultivars of native species are fairly close to the
native populations of their origin; I suspect that day length due to more
southerly origins might be the major problem. Humans will want to select
for hardiness and day length adaptation similar to that of the natives in
any case. I presume you will be growing without pesticides and and will
want or will select over time, cultivars that are tolerant to the local
conditions of disease and insects.

The native red mulberry population Morus rubra is in big trouble already, 
as its numbers are small and the landscape is full of Asian Morus alba and
some crosses. You will probably want to emphasize Illinois Everbearing
which has the merit of carrying and perpetuating some Morus rubra genes,
being reportedly a cross. Reliably pure Morus rubra of Ontario (or even
nearby) genetic origin is very hard to find from commercial sources or any

I don't know whether Korean nut pines are able (or if able, likely) to
cross with the native white pine. Ernie Grimo would likely know something
about this. How do their chromosome numbers compare?

The effect of European settlement on the local wildlife has already been
pretty drastic, especially if you are in a farming or suburban area.

If you don't do your permaculture thing successfully on your land, what is
its alternative fate? I doubt that you have enough land to support your
family with "unimproved" native species for food.

For ornamentals, I think there is a good argument for relying mostly on
native species of fairly local genetic origin.

If you have a significant area of forest that you manage sustainably and
restore to  a diverse species mix of the area, and if you establish native
and more or less local herbaceous species on your land, and you farm
organically, you will be of great benefit to your local ecosystem. Don't
sweat the details too much.

As an aside, cooking pears like Catillac are reputed excellent keepers,
and pears are fairly easy to grow if you don't push them too hard re
fireblight. On the basis of reading and no practical experience, if you
have a taste for cottage pudding and like foods, you may find them worth
some experimentation.

I would say, don't leave yourself too vulnerable to unseasonable frosts.
There are reasons why herbaceous crops and animal husbandry have

Doug Woodard
St. Catharines, Ontario, Canada

> As I plan my gardens and orchards, the back of my mind brings forth the
issue of cultivars and their possible hybridization with native species.
Everything I've learned in both Ecosystems Management and Environmental
Technology programs taught me that it is generally unsound to grow
cultivars in areas where there is even a slight chance that they may
pollute the gene pool. The Quote below sums up what I was taught:
> "In many cases, a native plant or cultivar brought from out of state is
not adapted to Colorado and may hybridize with Colorado plants,
> the local gene pool. Cultivars may flower too early, fail to set seed,
show poor diseases/pest resistance and fail to thrive due to climatic
differences. No one really knows what effect these cultivars will have
> the wildlife that depend on local native plant species for food. If a
local native plant's bloom period, color, or frost hardiness is changed,
it could have a drastic effect on the hummingbirds, bees and other
wildlife that may utilize them."
> Then I started reading permaculture books and websites to find that
> native species are encouraged in this school of thought, cultivars are
widely used. I understand that this is usually because the cultivars
> been specialized for human use but I struggle with that and ask; is it
worth the price of screwing the next generation of a given species? Or
> what I have learned just paranoid hard-lined rhetoric that has no base
> fact? Maybe my teachers are looking at humans as being outside of nature
when really we are a force of nature and therefore if we have the means
and inclination to plant cultivars, then so be it.
> I want to err on the side of caution but there are some plants that are
tempting me to hop the fence to the other side. I recall for example how
tough it is to crack a native black walnut, and how little meat there
> Similarily with regards to meat size is Korean Pine nut. Grapes,
mulberries, and strawberries, are just a few of the plants that I'd like
to grow cultivars of but am worried about doing to their native
> what GMO's are doing to corn, and canola, etc. The last thing I want to
> is a Monsanto-like monster to my local ecosystem.
> What is your take on this issue?
> Travis

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