Growing Milkweed
Finding Milkweed | Growing Milkweed |
Catching Monarchs | Making a Cage |
Rearing Monarchs
Stratification
Most seeds of temperate plants should be vernalized
(cold treated); this ensures a higher germination rate than if seeds are sowed without
this pre-treatment. Many of the southern species, such as tropical milkweed, will
grow without cold-treatment. The most successful means of milkweed vernalization
is through stratification. By stratifying,
or subjecting seeds to a cold/moist environment for a short period of time, you
simulate the conditions of a seed's natural break of dormancy that occurs when the
seeds spend the winter in the ground. To stratify, first obtain a substrate. Peat
has been found to produce the best results, in addition, peat/clay also work well.
Secondly, moisten the substrate with water and place the seeds in the cold soil.
Store the seeds in a dark place (a refrigerator crisper works well) with a temperature
of approximately 5°C for a minimum of 3 weeks up to 3 months.
To allow for natural stratification, sow collected seeds directly into a mulched
bed in the fall and the seed will germinate the following spring.
Germination / Transplantation
If
you have grow lights or a greenhouse, it is best to start your milkweed seeds indoors
a couple of months before you are able to transplant them outdoors. We fill the
seedling trays approximately ¾ with potting soil (light, well-drained soils
work best for most species) and scatter 3-4 seeds per cup and then cover the seeds
with an additional ¼ inch of soil. The soil is then fully saturated with
water and placed either in a sunny window or directly under the grow lights; they
need a lot of light and warmth to germinate and grow. It's best to keep the temperature
at 26/24°C day/night with a 16-hour photo phase. Keep the soil moist, but don't
overdo it. If the seedlings are too wet, fungal growth can occur and kill the seedlings.
The seeds will take approximately 10 days to germinate. Once there are 4 true leaves
on the seedlings (the seedlings will be approximately 3 inches tall), the plants
can be transplanted into your garden. Most milkweed species do best in full sunlight,
so choose an open area with lots of sun. Plant the seedlings 1-2 feet apart. The
seedlings should be watered frequently; mulch can be used to help hold in the moisture
around the plants.
For
indoor use, plant the seeds just beneath the soil surface using a rather deep pot,
as they have a long taproot. Once the plants are in the seedling stage, fertilize
once a week. To encourage fullness and more leaves, cut back the top of the plant
when it is about 30 cm high to promote branching. It takes at least a month for
the plant to be ready for the larvae to eat. Once the plant is big enough, you can
simply place the entire plant, pot and all, into the cage. After the larvae have
eaten the leaves, simply cut the plant off about two inches above the soil and new
shoots will grow in 3-4 weeks.
When planting seed outdoors, keep in mind that all plants have optimal soil temperatures
for germination, which makes propagation a little more difficult. It is best to
plant the seeds as early as possible, but make sure that you plant after the last
frost.