Thanks to the Horticultural Society of South Jersey for providing these Monarch Habitat Garden Kits!
Quick Link: Monarch Kit Planting Guide Printout
Whether you’re replacing part of your lawn with beneficial native plants or just adding to existing garden beds, you can look forward to beauty and increased wildlife activity around your home. And you’ll be doing your part to boost monarch butterfly populations, which have declined by 80-90% thanks to habitat loss and widespread pesticide use.
These garden kits include two species of milkweeds (Asclepias). Plants of this genus are the only ones monarch butterflies will lay eggs on, and they are the exclusive food source for monarch caterpillars. The disappearance of milkweeds from our landscapes is the main cause of declining monarch populations.
But milkweeds aren’t all that monarchs need. The adults also need abundant nectar sources in the summer and early fall to fuel up for their long migration to Mexico. The nectar species included in your kit have been chosen for their attractiveness to adult monarch butterflies. In other words, these kits can create a full habitat for monarchs. And as a bonus, these plants will support many other beneficial butterfly, moth, and bird species.
Your kits are made up of landscape plugs, and if you’ve never worked with them before, you may find yourself thinking, “Wait, you mean that 1 foot wide tray holds enough plants for a whole garden?” Yup, that’s exactly what we mean. Plugs are one of the most economical and easiest ways to quickly establish a full scale planting. Yes, they’ll take a little longer to reach full size. But with their well-developed root systems, most will reach flowering size in one growing season, they’re easy and fast to install, and they’re a fraction of the cost of container plants.
Establishing your Monarch Garden – Dense Planting is the Key
You want your garden to look great and to form a functional plant community that supports wildlife, promotes healthy soils, and crowds out weeds. If you leave too much space between your plants, you won’t be able to meet those goals. Each plant is different, but we recommend roughly 12-inch spacing for the plants in our kits. This allows individual plants to support one another and form an intertwined plant community, which they aren’t able to do if they’re too isolated. The goal is that once your plants are firmly established, you don’t want to be able to see any bare soil in the garden bed (this may take up to a year).
The plants in each kit are fairly versatile, but you’ll get the best results in sunny or mostly sunny sites with average soil moisture.
For a naturalistic yet orderly look, we recommend massing flowering plants of the same species together in groups of 5. We also recommend avoiding placing your plants in rigid grids – these are wildflowers after all, not rows of corn.
Our other design suggestion is to keep the Swamp Milkweed and blazing star either in the rear or in the middle of the garden bed, depending on the layout as they are taller and the lower leaves on their stalks tend to fall off by late summer. So by not having them out front, you won’t notice their naturally bare stalks (plus you’ll provide extra shelter for young monarch caterpillars). None of these are hard and fast rules of course, but they’re good ways to achieve the striking visuals that wildflower gardens are capable of.
Planting Your Plugs
Don’t wait too long to plant your plugs after receiving them. But if you can’t do so right away, just keep the trays watered and out of too much direct sunlight – the small soil volumes of plugs can dry out very quickly in their trays.
If you’re planting into an existing garden bed, make sure it’s weed-free prior to planting. There’s no need to till the soil – that will disrupt the community of microbes and bring weed seeds to the surface.
If you’re replacing existing lawn with a pollinator garden (good for you!), you’ll need to get rid of your turf and the roots – simply tilling it will lead to roots resprouting new grass. It’s best to avoid herbicides like glyphosate as they pose a danger to other plants, beneficial wildlife, your newly planted plugs, and any humans in the area. For large areas, you can rent sodcutters to remove turf, but for smaller beds like you’d need for these kits, a good shovel will do the job. Just dig down a few inches, then slide the shovel blade under the turf roots to pry them up. Be as thorough as you can. The work goes much easier if you sharpen your shovel blade with a file and wet down the turf you’re removing with a hose (it will be heavier, but come up easier).
Once your planting area is ready, it’s easiest to lay out your plugs prior to planting. Once you’re satisfied with the placement, just dig holes as deep as and slightly wider than the plugs, gently slide them in, and fill in and pat down the soil around it. I like to use a soil knife (or hori-hori) for plugs, but a regular garden trowel will work fine. You may want to loosen up the roots of the plug and flare them out a bit before planting to allow them to reach out into your soil. With hardy native plants, you won’t need soil amendments. Thoroughly water each plant, making sure to direct water to the roots until the soil is thoroughly moistened (and no air pockets remain around the roots)
We recommend applying a light layer of mulch (about two inches deep) between plants to keep the soil from drying out and help keep weeds at bay. Too little will allow weed seeds below to germinate, and too much will keep water from draining into the soil (and overly moist mulch can germinate weed seeds as well). Make sure that the mulch does not come within an inch or two of the stems or leaves of the plants themselves, but merely covers the bare ground between them. Shredded-leaf compost makes great mulch, or you can use pine needles or finely shredded hardwood (avoid those dyed mulches – they’re made of shredded pallets and wastewood which often contain pesticides and other harmful chemicals)
Plants will require regular watering until firmly established – even species that are drought-tolerant. Water every day or two for the week (unless it rains), and less frequently as they become established. During the second year, the plants should be pretty well established, and will likely need no water at all barring unusually extreme weather conditions.
As fall comes approaches, your plants will enter dormancy. We recommend leaving them as is. The dried stalks and any seedpods will provide winter interest to your garden, not to mention food and shelter for birds and other wildlife. In early spring/late winter, cut down all of the stalks to about 3-4 inches or so. Better still, go over the bed several times with a mulching mower set at its highest level (watch out for shrubs that might be nearby). The shredded plant material will act as mulch and will be just enough organic material to feed your plants.
Your plants will reemerge in the spring ready for another season. Note that it’s common for many milkweed species to be among the last native perennials in our area to send out spring shoots, usually in early May.
More Design Tips
There are no hard and fast rules here – feel free to get creative, and obviously adjust as necessary based on the layout of your site. Space individual plants at 12 inches on center (so a 25-plant kit will fill 25 square feet). If your site is bigger, we recommend keeping the planting tight, rather than stretching it out to fill your space. That way the planting will stay dense and form vibrant plant communities. Your plants won’t be as happy if they’re too spread out (plus you’ll be more likely to get weeds in the gaps) – you can always expand the garden later or even divide many of the plants as they mature over the years.
If you want to go for a more wild look (almost like a meadow), you can distribute species randomly. But for a more ordered yet still naturalistic look, we recommend massing species together.
Since this garden kit was designed as monarch habitat, blooming commences in the summer and continues through early fall to maximize the benefit for monarchs’ lifecycles. In order to add an extra season of interest, you may want to plant some spring-blooming native perennials nearby or even intermingled within your garden.
We’ve offered two layout ideas below for differently shaped beds, but don’t feel bound by these.
Note that for those who are receiving their kits through the Collingswood Monarch Project, showy goldenrod (Solidago speciosa) has been substituted for summer phlox.
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