By Nick Novick, Small Planet Landscaping
Many ecologically-inclined homeowners, landscape practitioners, and property stewards are increasingly turning to meadows and meadow-inspired designs, not only for their naturalistic beauty and ecological benefits, but also to possibly to reduce management inputs for their sites.
For those who may not have much previous experience—and are seeking a streamlined process to get going—ready-made seed mixes may seem like a quick and easy way to get started on their vision of a colorful, dynamic landscape. While these mixes do save some time and effort, and possibly money, they often embody pitfalls. I’ll offer some reasons why I think that—with a few possible exceptions—using these for most projects is not generally a good idea.
To be clear, I’m not talking about the truly clueless concoctions like Meadow in a Can™, now mercifully defunct, although it has been succeeded by an equally horrid Meadow in a Can Jr. There should be a law against selling these. One can now find pre-mixed combinations of seed offered by various upstanding nurseries, retailers, and even garden centers. Catalogs and websites list mixes labeled for pollinators, shady areas, dry soils, medium soils, wet soils, clay soils, erosion-prone areas, roadside areas, septic field mixes, and most any other kind of setting one could imagine.
At first, these might seem like a great thing—a ready-to-order mix tailored to your particular site conditions. However, the site you have rarely matches any kind of “average” or “typical” set of conditions used to define it. The site may have subtle—or not-so-subtle—variations in the macro conditions of sun exposure, moisture conditions, soil characteristics, etc., that are different across the area, requiring different or additional species to suit those variations. Sometimes the species included in the mix might be adaptable enough to still be viable for those divergent conditions. But when you design the mix yourself, you can easily make any adjustments to cover either side of the conditions you anticipate. Or you can also develop a separate mix for those areas.
High species and structural diversity are key to creating a resilient, stable plant community more able to resist and recover from disturbance.
With some mixes, especially those that might be called “economy” or “contractor” mixes, species diversity might intentionally be limited to keep the overall cost down. Although this may be important for some projects, it comes at the expense of species diversity. High species diversity confers a number of desirable characteristics to a project. Some of these mixes lack particular species that may be especially useful for some ecological role in the meadow such as for support of a particular rare or endangered pollinator, but that seed may be relatively more expensive than average, or harder to source, so they are left out in the interest of economy. Indeed, a number of mixes I’ve seen are lacking in terms of plant species that are useful in a wider, ecological context.
Sellers that are primarily oriented to, perhaps, somewhat less discriminating homeowners as opposed to professionals, often include a number of non-native or regionally inappropriate species. Similar to the Meadow-in-a-Can™ approach, a number of these might be annuals. Usually, the intent is to stoke maximum bloom as quickly as possible to satisfy possibly impatient buyers. Most native perennials are notoriously slow to establish. If an entirely, or even predominately native-based meadow is what you’re after, you need to carefully check the species list on these to see if they meet your needs.
Spotted horse mint (Monarda punctata), Black-Eyed Susans (Rudbeckia hirta), and Canda wild rye (Elymus canadensis)are some species commonly used to fill the early-successional time niche.
Mixes can also be problematic because the competitive levels of the plants represented in the mix are mismatched. I’ve seen mixes which include one or more rather aggressive species such as switch grass (Panicum virgatum), big bluestem (Andropogon gerardii), or wild bergamot (Monarda fistulosa) amongst a number of other somewhat more companionable components that can easily overwhelm those less competitive plants. Over time, the planting can become dominated by these more assertive plants, reducing diversity and possibly lowering visual or aesthetic interest. This can happen relatively quickly on smaller sites. Although one can intentionally design a planting with a limited range of species where a few dominate, this shouldn’t be what a project evolves into if the intent is something more diverse.
Many mixes are not ecologically sound. These often don’t include adequate species diversity to cover the various niches in the plant community that will grow from the seed over time. When we consider a meadow’s year-to-year time niche, in the context of an early successional community that will change over time, plants that are fast to establish—ruderals or pioneers, in the ecological jargon—need to be included along with species that take longer to establish and mature. Since they often bloom relatively soon after seeding, some mixes include a preponderance of the pioneer species, to the exclusion of a broader component of longer-term plants that take longer to mature. In addition to the time niches, the various structural layer niches need to be filled to ensure high resiliency and stability. Mixes are sometimes sorely lacking in this regard.
Culver’s Root (Veronicastrum virginicum) is an example of a longer-term forb can be long-lived in a meadow setting, but it can take 4–7 years to mature to flowering stage when starting from seed.
My biggest issue with these mixes is that whoever buys them and tosses the seed around on their project site often has no way to know exactly how many seeds of each species they’re putting down. We know the total weight of the seed mix, the area it’s being applied to, and we know what the species are, but in what proportion? How many seeds of each species are in a unit weight of the mix?
When constructing a seed mix from the ground up, you develop a list of species appropriate to the site, fulfilling the various ecological niches and providing an overall appealing appearance. Specific sub-mixes or overlays may be called for due to variations in conditions in different areas of the site.
Since grasses and grass-like plants are essential to the long-term success of a meadow, the designer determines the relative ratio of grasses, sedges, and rushes component to the forbs component. Within each cohort, a percentage is assigned to each plant species for how much of the mix it will comprise. A bit of simple math produces the number of seeds of each species that need to be sourced and ordered. Since seeds are sold by weight, the number of seeds needed for each species is converted to weight using the seeds-per-ounce data provided by your favorite source, and that’s what you order.
You may elect to have the seed mixed together by the supplier, or you can do it yourself, which provides at least a couple of benefits. As you open each envelope or bag, you can marvel at the variety, sizes, colors, etc. of the seeds and begin to associate them with the species. This can add to the depth of your understanding and appreciation of the whole process. It also allows you to hold out certain species from the general or main mix that you may want to use in some areas and not others, tall drifts here and there, or some isolated groups of more structural plants, for example.
Pre-constructed mixes relieve you of having to do any of this, but, in many cases, you will have no way to know how many seeds of each species in the mix you actually put down, the relative numbers of seeds of each species as a percent of the total, or the total number of seeds you apply per unit area. To be fair, some suppliers will provide some of this information, for example, the percentage of each species (almost always by weight), but then you have to convert back to seed numbers to make any kind of useful, objective evaluation of possible issues. This is because the size and weight of seeds varies so much between species. They can range from the size of a period at the end of one of these sentences to the size of your pinky fingernail, and from a few thousand to hundreds of thousands of seeds per ounce.
Thus, when you’re trying to evaluate the success (or issues) as you monitor the germination and early growth stages of your project, you’re operating in a serious information deficit, since you really don’t know these details of the seed mix. There may be more or less of certain species manifesting than you were anticipating and you might be wondering, “Should I use more or less of this or that species?” Because you don’t really know what you started with.
A diverse species meadow, four years after seeding. One can already see species beginning to sort themselves into groupings based on subtle variations in site conditions.
Over time, after you’ve had the experience of creating your own mixes, knowing the relative proportions of seed of different species, and seeing how the plants respond on different sites, you’ll be able to develop if not a recipe, at least some general guidelines and proportions of species that work well with each other in different settings.
All this said, one can imagine situations where a meadow mix could be useful. There may be rare occasions where you’re on a short timeline, and you need something quickly and don’t have time to work up a detailed list from scratch. You may have a temporary project that will be converted to something else later, or ecological concerns might not be an overriding consideration. Even then, some mixes are better than others. Look for high species diversity, species that are adaptable to conditions slightly either side of their ideal preferences, and little or no cheap, non-native annual fillers. Those use cases would be the exceptions to what I’ve always considered the rule that’s it’s almost always better to conceive and put together your own seed list based on the factors discussed above.
Based in eastern Massachusetts, Nick Novick operates Small Planet Landscaping, which has been providing environmentally sensitive landcare services for over 20 years. These days, designing and installing landscapes based on native-plant communities, including meadows, comprise most of that work. He is a former ELA board member and newsletter editor.