Invasive Plants 101
Control and removal of invasive species is one of the
mostimportant things to do when restoring or maintining a natural
area. Invasive species are non-native plants that have adapted too
well to growing in a certain area. They are often not eaten or
controlled naturally because their predators are not present in the
new ecosystem. Invasive species will out-compete and displace
native plants and drastically reduce the ecosystem value of an
area. This document will give a brief overview of the most common
and/or devastating potential invasive species at the Desert
Centre.Controlling weeds in gravel and among stepping-stonesIn the
parking lot and around the picnic areas, weeds such as thistles,
unwanted grasses and (Creeping vine) can be easily controlled by a
few applications of 7% pickling vinegar sprayed on the plant on a
hot, sunny day. The vinegar-sun combination burns and bakes the
plant leaves, essentially killing the plant. However, this method
is non-selective and will sterilize soils, so is not recommended
for use in the native garden and should never be used in natural
areas.
Guide to common invasive plants at and around the Desert
Centre:
Knapweed (Centuaria sp)Aggressive, taprooted tumbleweed. Easily
pulled, gloves are needed. Re-seed heavily with competitive native
species after larger patches are removed. Due to strong
allelopathy, cleared patches must be continually monitored for new
knapweed shoots, however very small (inadvertent spread.
Puncturevine (Tribulus terrestris) RED ALERT. REMOVE ON
SIGHT.Highly aggressive mat-forming annual with viciously thorned
seeds. If seeds have not yet formed, find the central taproot and
gently but firmly pull the entire root out. If the root snaps, try
and dig it out without causing too much disturbance to the soil. If
seeds have formed, pull plant as above, but be very careful not to
let seeds fall. After removal, search the invaded area thoroughly
for any fallen seeds. As this plant is not established on the
Desert Centre property, it is vital that the occasional invader is
removed immediately.
Babys Breath (Gypsophila paniculata)Deeply rooted biennial
tumbleweed with an extremely deep taproot. Extremely difficult to
eradicate once established, so plants MUST be removed on sight.
Best to remove just after flowers form. Taproot is extremely long,
but does not have to be completely removed to halt regrowth. Dig at
least 6 inches below the surface when pulling babys breath to
ensure full removal or root crown. Seed with competitive species in
disturbed area. As Babys Breath has not established on the Desert
Centre property, removal of the occasional invader is crucial.
Toadflax (Linaria spp) Nearly impossible to eradicate once
established. Leave this species as is. Biocontrol in effect.DO NOT
ATTEMPT TO PULL.
Tall Tumble-mustard (Sisymbrium altissimum)Due to its shallow
taproot, mustard is very easily pulled. A firm tug is usually all
that is needed to remove the entire plant and root system. Produces
staggering amounts of long-lived seeds, so mechanical removal is
best supplemented with mowing (before it goes to seed!) and
competitive seeding with native plants
ThistleWavy-leaf thistle is the only thistle native to the
Okanagan region. It is distinguished from other thistles (Canada
thistle, Scotch thistle, etc) by XXXXX. All other thisltes can be
pulled blahblah
Creeping mat thing?? Delicate mat-forming (perennial?) Because
it easily shreds, be gently, yet firm when pulling. Vines will
re-root along their length, so pull from the outside of the plant,
working towards the main taproot. It can resprout from pieces left
behind so be sure to gather all remnants of the plant after
removal. Vinegar spraying is highly effective for this species.
Showy Milkweed (Asclepias speciosa) ***Though it is native and was
intentionally planted on the Desert Centre property, milkweed is an
extremely hardy, fast growing plant that spreads via seeds and
vegetative root shoots, as well as broken-off pieces of root. As
such, it is difficult to control in a cultivated garden. Seed pods
must be cut once developed leave some to mature for harvesting seed
and new stands should be pulled and dug up once found in unwanted
locations. Due to its aggressive nature, milkweed is a good
competitor with non-native invasives.
