Tag Archives: Transplanting

The Prairie Ecologist Article: Lessons From a Project to Improve Prairie Quality – Part 2: Overseeding and Seedling Plugs

Last week, I posted a summary of some findings from a long project to enhance prairie habitat. I focused that post on the lessons we learned from the fire/grazing management portion of the project, including impacts on regal fritillary butterflies. This week, I’m looking at the other half of that project – overseeding and adding seedling plugs to our degraded prairies in order to increase plant diversity. As with last week, you can find all the gritty details, including graphs, tables, and more, by looking at our full final report.


Maximilian sunflower is one of the species we’ve found easiest to establish in degraded prairies. (These particular sunflowers are for illustration only – not from an overseeded site.)

During the five years of the project, we overseeded approximately 500 acres of prairie – focusing mostly on degraded remnant (unplowed) prairies that were missing many characteristic prairie wildflower species. We harvested our own seed from nearby sites, and broadcast it on degraded prairies right after burning them. The prairies were managed with patch-burn grazing, so cattle grazed those burned areas intensively for the remainder of the first growing season and then focused their grazing elsewhere in subsequent years. To measure success of the seedings, I used replicated plots to count the number of new plants that established from seed. Most of the seedings included multiple seeding rates, so I was able to look at the effect of seeding rate on establishment.

In addition to overseeding, we raised and transplanted more than 800 prairie and wetland seedlings into seven different sites, and added several hundred more seedlings to our nursery beds for seed production. Most transplanting was done in the late spring, and plants were watered on the day of transplanting but afterward. We marked (GPS and flags)and attempted to re-locate seedling plugs to evaluate survival, but that didn’t work out very well, and we didn’t find a lot of the plants we’d plugged in. Some of those plants surely died (which prevented us from finding them), but for others, flags disappeared and GPS points weren’t accurate enough to lead us to the small plants we thought were probably there. We did find some, but our estimates of success are pretty fuzzy.

We learned two major lessons from this portion of the project:

1. Overseeding after a burn in a patch-burn grazed prairie can re-establish at least some missing plant species, but the use of a high seeding rate is important.

2. Overseeding seems to be more cost effective than seedlings, assuming abundant seed can be obtained relatively cheaply.

In tallgrass prairies further to the east of us, people have had pretty good, if inconsistent, luck with overseeding prairies without necessarily having to suppress the vigor of surrounding vegetation. We’ve tried that here, and have seen very low success, maybe because our drier climate (25 inches of precipitation per year) increases competition for moisture? Regardless, our best results have come from seeding after a burn – for good seed/soil contact – followed by grazing of the dominant grasses that appear to be the primary competition for new seedlings. Patch-burn grazing works well, but we’ve also had good luck in the past by just grazing intensively for a month or so after seeding, and then pulling the cattle out.


Trails from our ATV and broadcast seeder in recently burned prairie. Broadcasting after a burn helps get the seed/soil contact we need. Experiments with light harrowing as a way to get even more soil contact haven’t shown any obvious results. Note the absolute straight lines I made as I planted this site…

Seeding rate was very important. We started by seeding at about the same rate as we use when we converting cropland to high-diversity prairie – about 1-2 lbs of bulk forb seed per acre. As the project went on, we went as high as 8 lbs, and continued to see better results. At least in our prairies, seeding smaller areas with more seed seems to be more effective than spreading limited seed over large areas.

Because others have incorporated light tillage or harrowing to suppress competition and increase seed/soil contact, we tried some of that as well, but our results were mixed. Some tilled plots showed very high establishment, but others showed less than non-tilled plots. We did find that when we tilled a few inches deep, we didn’t seem to kill any plant species – remembering that these are degraded sites already. I would definitely not recommend that others try tillage on a large scale, but in small plots within degraded grasslands, it’d probably be worth some more experimenting. We had a beautiful set of replicated tilled plots that I hoped would clarify the situation in 2012, but the severe drought overwhelmed that attempt.

Even at our highest seeding rates of 8 bulk pounds of forb seed per acre, the density of established plants was relatively low (in our best sites, we established around 150 new plants per acre) but hopefully high enough to create self-sustaining populations that will grow over time. The plant species that established most readily included:

Maximilian sunflower (Helianthus maximiliani)
Sawtooth sunflower (Helianthus grosseserratus)
Stiff sunflower (Helianthus pauciflorus)
Illinois bundleflower (Desmanthus illinoensis)
Entire-leaf rosinweed (Silphium integrifolium)
Wild bergamot (Monarda fistulosa)
Black-eyed Susan (Rudbeckia hirta)
Purple & white prairie clover (Dalea purpurea and D. candida)
Canada milkvetch (Astragalus canadensis) – in some sites
Illinois tickclover (Desmodium illinoense) – in some sites
In terms of seedlings, we have found that most prairie plants are easily grown in greenhouse situations (with some exceptions) but that some take more than a year to germinate, and then perhaps a full year or more to grow large enough to transplant. When we planted the seedlings into prairies, we clumped them together in groups of 5-10 plants to help form populations that could cross pollinate, and to make it easier to find at least one of the plants we’d put in.

TNC greenhouse Platte River Prairies.

Compass plant seedlings and others in our greenhouse.

We had success with seeding plugs in some situations – particularly in terms of getting wetland sedge species established in restored wetlands – but transplant survival in degraded mesic prairies was mixed at best. Most of our transplanting was done in the late spring, as we hoped to synchronize our planting with the wettest time of the year, but we may experiment with more fall planting in the future. We felt that many of our seedlings may have died because they weren’t in the appropriate soil conditions, which we had to guess at since there were no existing populations of most of the species we were transplanting. Broadcasting seed is probably a better way to match up appropriate plant species with their specific microhabitat requirements.

In our situation, it appears that overseeding is a cheaper and more efficient way to increase plant diversity in degraded prairies. Of course, one big reason it makes sense for us is that we have existing capacity for large-scale seed harvest. If enhancement of degraded prairies is a high priority for a landowner or land management entity, it might make sense to build their own seed harvest capacity. That doesn’t necessarily mean large investments in equipment or people, though a pull-behind seed stripper or combine can be a nice way to harvest large amounts of seed quickly. Large amounts of wildflower seed can also be harvested by hand (our typical method) if you are efficient and organized.

By Chris Helzer from The Prairie Ecologist Website

For All Your Native Wildflowers & Seeds Visit Us At Our Website Native Wildflowers & Seeds From Ion Exchange, Inc.

Planting Perennials in the Fall

I have planted small plugs up through Thanksgiving and we are on the border of Zone 3 and 4 here in NE Iowa. The root system is the most important part of the plant any time that you transplant. The fall can be deceiving and people who purchase plants this time of the year are sometimes disappointed that the tops are shaggy or sometimes non-existent. Don’t get discouraged. Take time to observe the root system. Select plants that have healthy roots. If the root system is dark and slimy, it is not a good plant and might even be dead. Choose plants or plugs with turgid, proper color and are not root bound. Don’t forget…plants have different colors of roots so become familiar with the colors. Also the density of the root system varies with different plants. For instance: Prairie Dropseed has a fine reddish colored root system while Cardinal flower has a very white root system that is very dense. Don’t compare one species to the other. Only compare same species with each other when checking the root system. So purchase your plants now and get the jump on next year as your plants will spring forth and be way ahead of those later plantings in the spring or summer.

Howard Bright – Ion Exchange Inc.

This autumn, consider planting perennials. There is no reason to wait for spring – fall is a perfect time for planting!
Editor’s note: This article was originally published September 8, 2008
Reprinted from Dave’s Garden

In the spring, we are deluged with catalogs stuffed with pictures of beautifully perfect flowers and plants. “Buy me! Plant me!” they cry. The nurseries fill with plants, live and in person, all needing good homes. “Resist,” I say. “The time is not yet at hand!” Planting perennials in the fall is a kinder, gentler way to plant.

Perennials planted in the spring have a tough row to hoe. They must:

* Develop an entirely new root system

* Adjust to life outside the greenhouse or nursery

* Produce a crop of flowers (or lovely foliage, or whatever it is you’re expecting of them)

* Risk being planted too soon, before they have “hardened off” sufficiently

* Risk being planted too late, in some of the most taxing conditions for a plant: the heat of summer

Many of the wiser mail order companies won’t even ship during the hot days of June, July and August. I recommend the more nurturing method of planting perennials in the fall. If you plant your plants at least six weeks before the first freeze is likely to occur, you’ll give them a chance to conserve their foliage and flower development in favor of root growth. If the roots are there, the plant will be there.

One of the strongest arguments in favor of fall planting is a good one for knuckle-heads like me: by fall, you know approximately what the plant looks like, how tall and maybe even what color it will be.

Platycodon very busy blooming – do not disturb!

This lovely balloon flower on the right (Platycodon) usually flowers during the heat of July. Don’t plant it now! It’s hard enough on the poor thing that it has to flower. Don’t make it suffer transplant shock as well!

This next specimen, below, may look unhealthy, but it’s the same type of plant, Platycodon, at the next stage of its life cycle: setting seed and hunkering down for the winter. If you see a plant like this for sale, especially if it’s marked down, by all means, buy it and plant it! Make the hole nice and deep, back fill with amended soil and consider adding fertilizer or moisture crystals if appropriate for the plant and your climate and soil. Don’t forget to water thoroughly after planting.

Platycodons finished blooming. They’re ready to be planted.

My husband bought around 20 balloon flowers just like the one on the left for $2 each one fall and planted them as a border to a path. I may have found Dave’s Garden in my effort to discover just what, exactly, he was getting us into! But sure enough, the next July, they looked something like this:

Now it’s almost a tradition. In the fall, we shop for bargain plants, and then plant them before winter. One year the snow came earlier than we expected, and the bed he was working on wasn’t quite finished. So that year, he actually planted perennials in half an inch of snow! What you Southerners may not realize is that snow only means the air up high is cold, not the earth. The new bed didn’t freeze for another couple of months, giving plenty of time for the heuchera, viola, columbine, geum and potentilla to get established. They were all lovely the following spring, and most of them are still fighting it out.

So procrastinators, take heart. The best time to plant many flowering perennials may be right now!

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