Gardening with Forest Park: Cover Crops & Fedges

Back in the third week of October, after a week of pulling out the summer display, tilling, preparing, re-shaping, removing all of the rock and later putting it back, the annual garden beds at the Boathouse were ready to be replanted for the spring tulip display. With soil knives in hand and bulbs laid out, Eric and I, alongside our volunteers, worked through a thunderstorm and continuous downpour to plant the bulbs we had laid out  even though we were all soaked and a bit muddy. Although we were delayed planting the rest of the tulip bulbs by a week, on a much dryer day we finished planting around 8,000 Tulipa ‘Emperor White,’ 1,250 wonderfully scented Hyacinth ‘Blue Jacket’ and 100 Fritillaria rubra (Red Crown Imperials). This year we included 2,000 Viola ‘Matrix Coastal Sunrise Mix’ (Pansy) surrounding the annual beds, tucked in nicely with pine straw mulch.

In my opinion, we have the very best volunteers helping us in the Boathouse zone, and their dedication has allowed us to pull off some crazy flower displays over the past two years. 

Even with the garden ‘put to bed for the winter,’ new life was appearing over the surface of the garden. “What are the green plants growing across the annual garden?” many Park visitors asked. Well, the green seedlings growing across the annual display are not weeds, but a seeded winter cover crop. Our warm weather in late October into early November was perfect for starting these seedlings.


Why plant a cover crop?


At home, flower gardeners and vegetable gardeners alike may be looking for new and more organic approaches to solving soil issues. In past articles, I have written about the importance of mulching flower beds, but have you ever thought of planting a cover crop? A cover crop is temporary, planted between vegetable crop cycles or when flower beds are bare. This year, we have tried to demonstrate to the public this organic gardening practice in an unusual way – by planting a cover crop in our tulip beds.

Good soil structure is a precious resource that should be protected. It can take years to get a garden space back to what it should be. Unfortunately, we often take our soil for granted. Two ways we can help improve our soil structure is through the use of brown mulch (hardwood bark, leaf matter, and what I introduced to us last year – pine straw) and green cover crop. Cover crops should not be limited to vegetable gardens, but even annual flower beds can benefit from them. Besides the border of pansies around the current Boathouse display, we planted seeds of Trifolium incarnatum (Crimson Clover), Erysimum x marshallii (Siberian Wallflower) and Papaver nudicaule (Icelandic Poppy).

The use of a green cover crop at the Boathouse helps the soil structure in a few ways, including:

  • Protects Soil: A cover crop protects soil from wind and rain erosion and compaction.
  • Holds nutrients: Takes up vital nutrients such as Nitrogen, which may leach out of the soil structure during the winter months.
  • Builds soil structure: Adds organic matter.
  • Promotes ‘Living Soils’: Provides food and habitat for soil macro and microorganisms.
  • Provides seasonal interest: A green carpet of cover crop can provide seasonal growth in a bed that would otherwise be bare.

Using a cover crop isn't the only thing that's new with this season's Boathouse display. If you've visited recently, you might also be wondering "What is that fence around the gardens at the Boathouse?"

Fedges are creative ways to make artistic natural fences for small gardens. 

Fedges are creative ways to make artistic natural fences for small gardens. 

Have you ever heard of a fedge? It is simply a cross between a fence and a hedge. Typically willow branches are used to weave in and out to create intricate patterns in this hand crafted fence-like structure. Willows are the plant of choice because their branches root readily. It is amazing that a single branch of a willow can be cut and placed directly in soil and continue to grow into a small tree. I first came across the concept when visiting Chanticleer gardens in Delaware, just outside of Philadelphia. They had created a series of small arching lines of living willow branches to help line a woodland path. This got me to thinking, What if we tried to recreate this very English Kitchen Gardenesque concept of a living willow fence in our winter/spring annual display here in Forest Park? If you have never seen one, come see our 18” high willow fence around the garden at the Boathouse. In our garden it serves a dual purpose: winter decoration and a physical barrier in the bed, which not only protects our spring bulbs below ground, but also provides support for our Emperor white tulips which will rise 20” tall in April. Make sure to stop by our gardens this coming spring to see this bulb display come to life!