Seed Collecting

Now that summer is almost over, thoughts turn to seed collecting. Many of our major successes in restoration at Pleasant Valley Conservancy have been due to judicious planting of the appropriate species. And most of the seeds we have planted were obtained by hand collecting, either by us or by very helpful volunteers.

Seed collecting is one of those restoration activities that most people like. Its not as popular as a controlled burn, but it is relaxing and enjoyable. There's the thrill of finding a nice population of the right species at the right time. There's the quiet, whishing through the tall prairie and listening to the birds. And there's the sense of accomplishment when you pour a full bucket of seeds onto a drying tarp or rack.

Right now, we are collecting the following species: savanna grasses (bottle brush and silky rye), Kalm's brome, Illinois and Canada trefoil, prairie cinquefoil, and side oats grama.

The equipment needed is simple: a bucket fastened to the belt with a clip, and a pair of good hand clippers (see photo).

We have prepared a useful guide to collecting prairie and savanna species, with collecting dates suitable for southern Wisconsin. Check it out.

Giant Ragweed

Hay fever sufferers know that now is ragweed season. Fortunately, I don't have any allergies. But I am greatly allergic to the tall patches of giant ragweed (Ambrosia trifida) that have come into several of our open savanna areas. Although giant ragweed is a native species, it is potentially invasive, and given the right conditions it can flourish. Since it is an annual, it should not have any long-term effects, but it can easily shade out small prairie plants.

This year we have a major affliction of giant ragweed in Unit 18, a potentially nice savanna area that we have been working diligently to restore. Last winter we removed many small honeysuckle bushes in this unit, creating a lot of bare-soil areas. Although we planted prairie and savanna species in all these bare areas in early April (after an excellent burn), prairie plants are typically slow in getting started. In the meantime giant ragweed has taken over. To keep it from setting seed, Chris is now mowing the large patches using our Stihl brush cutter. This should reduce the problem and in a year or two the prairie plants will hopefully be well established.

Even More Cream Gentians!

My 14 Aug post (below) is about cream gentians. After a slow start, this State Threatened species is now really thriving at Pleasant Valley Conservancy. Today we found 181 flowering stems in an area of the Valley Prairie about 25 X 300 feet. We could hardly walk in the area without stepping on a gorgeous plant!

The Valley Prairie was planted in November 2002. Because it varies from wet-mesic to dry-mesic, different seed mixes were used for different areas. The cream gentians were planted in the wet-mesic region and this is where the we found the plants growing today. The cream gentian seed were hand-collected at a prairie remnant in northern Dane County. Interestingly, we also planted three other wet-mesic species, bottle gentian, turtle head, and great blue lobelia, in the same area, but we found only the cream gentian in profusion. Perhaps the other species will show up in another year or two.

The Valley Prairie has been floristically interesting since the 2nd growing season, but in this, the 4th growing season, things are really taking off. Among other things, it is benefiting from the careful hand weeding that we did this year.

Interns 2006: Final Day

Our intern summer program has come to an end. University classes will be starting soon, and the interns will be moving on to other things. This has been a great summer for us, and we are sorry to see them go, but we wish them well in their future careers. They are leaving Pleasant Valley Conservancy in very good shape. It is almost impossible to find a bad weed.

Of course, "our" work is not finished. We will be starting serious seed collecting next week, especially of savanna grasses and forbs.

Sunflower Season

This is the season when members of the genus Helianthus (sunflowers) are blooming. They are mostly clone-formers and hence form patches, some of them large. We have lots of them, perhaps too many in some areas, but enjoy their colorful displays. The photo on the right is a woodland sunflower, probably Helianthus divaricatus.)

Unfortunately, the taxonomy of Helianthus is difficult, at times impossible. Here is what Voss (Michigan Flora, Vol. 3) has to say: "This is a notoriously difficult genus...with hybridization obscuring differences between a number of species. Some specimens will not work in this (or any other) key."

As an example of the difficulty, I found one specimen in the middle of the clone shown here which had leaves in threes instead of twos!

I spent quite a bit of time today collecting specimens from various locations for pressing and later identification. I know from previous years that we have at least six species. H. decapetalus, H. divaricatus, and H. strumosus are woodland-edge species. H. tuberosus and grosseserratus prefer wet areas, and H. pauciflorus is a prairie species.

We don't have any of the cultivated species, H. annuus. It is a nonnative annual that occasionally "escapes".

Further on Canada Goldenrod

A recommended control method for Canada goldenrod (see yesterday's entry below) is to cut all the plants in the clone at flowering, the time when most of the nutrients are in the stems. The idea is that this should starve the roots and set back the clone for future years. However, if there are "good" plants within the clone or nearby, they may be cut also, which is too bad.

Here is a way to avoid damaging good plants. Before cutting the clone, hand clip the goldenrod stems that surround the good plant(s), leaving a vacant area of about six inches. Then wield the brushcutter and finish off the clone. The good plants will be left standing among the dead goldenrod bodies. This takes longer than just cutting the whole clone, but should give the good plants a head start next year.

Chris and I tried this approach today. It looks good and we are looking forward to seeing the result next year!

Canada Goldenrod

Canada goldenrod (Solidago canadensis) is a perennial clone-former that is considered "potentially" invasive. According to Cochrane and Iltis (Atlas of Wisconsin Prairie and Savanna Flora), this is a polyploid complex plagued by hybridization and much weediness. It is one of the rare plants in the Wisconsin check list that is listed in every county in the state.

At Pleasant Valley Conservancy, we would erase the "potentially" from the first sentence above. There is no question that Canada goldenrod is invasive. It is widely spreading in our planted prairies, and we also find it, although not so rampant, in our savannas.

What to do about it? Even though it is a native, we don't want a whole field of a single plant.

Some years ago we got rid of a small patch adjacent to one of our prairie remnants (Unit 1) by hand pulling. After pulling every year for three years, we got rid of this patch. But the patch was only about 4 X 12 feet in size. In the Pocket Prairie and the Valley Prairie we have patches that are lots bigger than that.

Taking a tip from Steve Packard of Chicago Audubon, we have tried cutting the big patches, either in mid-summer or at the time of flowering. Last August I hand-clipped a patch that had 273 stems (I counted them). The advantage of hand clipping is that you can leave any good plants, which should flourish in the absence of competition. However, hand clipping is a slow, tedious process. Another approach is to cut the whole patch with a brush cutter. If this is done at the time of flowering, most of the nutrients should be concentrated above ground and the roots may get starved. At least they should get set back and other plants may get a good start next year.

Another approach that I have heard of is to spray the whole patch when it is just getting started (sometime in June, presumably) with an herbicide such as Transline or Escort, that is very active against members of the Sunflower Family. Neither of these herbicides affects prairie grasses. It's too late for us to do that this summer, but I plan to give the herbicide approach a try next summer.

Good and Bad Thistles

We have both good and bad thistles at Pleasant Valley Conservancy, and thankfully, the good far outnumber the bad. Three "good" species that we have are: pasture thistle (Cirsium discolor), swamp thistle (Cirsium muticum), and wood thistle (photo at right; Cirsium altissimum). The first two species were here before we started restoration, and the last one has now become established from seeds. We have transplanted greenhouse-raised plants of another native species, Hill's thistle (Cirsium hillii), and they seem to be thriving, so perhaps some day we will have four native species.

The two "bad" thistles that we are fighting are Canada thistle (Cirsium arvense) and bull thistle (Cirsium vulgare). Fortunately, we don't have major infestations of either of these bad thistles. We seem to be getting bull thistle under control simply by digging it out at the flowering stage (it is a biennial). Canada thistle is unfortunately both a perennial and a clone former. The recommended method for control is mowing at the time of flowering, and we have been doing this for at least six years, without any noticeable effect. (We did get rid of one patch in the Barn Prairie by use of the herbicide glyphosate).

Although Hill's thistle blooms in June, the other three are blooming now, and will continue blooming for another few weeks.

Thistle seeds are a favorite food of goldfinches, and we even had one make a nest in one of our tall pasture thistle plants.

Dealing with Grape Vines

Although grape (Vitis sp.) is native, it presents a real problem for the restorationist, spreading wide over the ground and shading out anything good under it. Grapes are really hard to get rid of, because a single vine can be many feet long and finding its start is a challenge. You start at the tip and work back toward the base, hand over hand, pulling it up as you go. But there is never just one grape vine, but a tangled mess. Often when you finally get to the base, there are four or five stems that must be cut and treated with glyphosate. Then the whole complex has to be removed from the site. Seven of us spent three hours this morning dealing with a single large grape vine complex at Black Earth Rettenmund Prairie. And we have lots more to do on future work parties.

Future Legacy Oak?

When we cleared undesirable trees from what is now the Crane Prairie, we uncovered a nice small bur oak (photo below), which we left. In another 50 years or so it should be a quite handsome open-grown oak. Although bur oaks are most commonly found on the ridge tops in our area, another of their habitats is the edge of wetlands. Very few bur oaks remain in this zone, probably because most of the wetlands were drained for agriculture. Every time I pass this recently emerged tree, I think about how it will look in 50 years or so. I am asking the young folks who are working with us to come back and visit Pleasant Valley Conservancy when they are 70 years old, and see what this tree has turned into. What a treasure it should be!

 

Visit: Guild of Natural Science Illustrators

The Guild's annual meeting was at the University of Wisconsin-Madison, and one of the field trips came to Black Earth Rettenmund Prairie and Pleasant Valley Conservancy. It was a delight to have such an enthusiastic and knowledgeable group. The prairies and savannas were in their full summer glory! The heat wave had moved east, leaving us with delightful weather. Leaders were Steve Richter and Tom Brock.

How to Work Outdoors in Hot(!) Weather

The whole country is having really hot weather this week and Tuesday was no exception. Our interns work on a fixed schedule, and we have them every Tuesday, rain or shine. (And today it really shined!) Kathie and I decided that the only way this day would work is if they started early, so we asked them if they could start at 6:00 AM. Since they all have considerable driving time, this meant some had to get up at 4:30 or 5:00 AM. But these folks are intrepid workers, and they were all on the job exactly at 6:00!

At 6:00 AM it was 86 F and by late morning it had climbed to 95 F. Fortunately, we had a lot of work in the savannas, where there is some shade. The day was spent pulling and digging Queen Anne's lace (Daucus carota), a rather invasive plant in our area. By the end of the day (3:15 PM), there was little of this plant to see, and the interns were able to go home and escape the heat.