Comparing Tree Nursery Techniques on Urban Farms

Commodities

Practices

This project, Comparing Tree Nursery Techniques on Urban Farms, focuses on white oak (Quercus alba) and hackberry (Celtis occidentalis) production from seed under two different growing techniques on farms in Detroit, MI. The two techniques are "air-pruned beds" and "in-ground row" production. Optimizing nursery production techniques in cities addresses the challenge of limited tree supply and food insecurity by exploring ways to scale up local tree production. Cities across the U.S. are setting tree equity goals and coordinating to increase tree canopy. However, most cities rely on rural, remote nurseries for tree stock which presents supply, costs, and transportation challenges. Transporting trees long distances has an appreciable carbon footprint, stresses trees, and may reduce viability as trees are less adapted to their new environment. Scaling up local tree production helps cities meet demand, creates income for farmers, increases food production, and improves ecosystem quality.

Urban farmers can cultivate over one hundred seedlings on less than 200 square feet. By studying different techniques for growing seedlings in urban tree production, farmers can incorporate a small tree nursery into their farm for added income. Trees can be sold or planted and eventually harvested for edible products or wood. Small white oak and hackberry trees sell for $10-30 per plant. Acorns are experiencing renewed enthusiasm for consumption across the globe, and although less popular, hackberry has potential as a nutritious fruit crop. These species are underrepresented in the Detroit landscape, enhance ecosystem quality, and represent fast and slow-growing varieties. Furthermore, farmers, city officials, and residents desire these species for their food potential, ornamental value, and ecological attributes.

Michigan State University Extension will partner with three farms to grow 1,500 white oak and hackberry trees from seed in air-pruned beds and in-ground rows.  Both methods are standard for starting trees but vary significantly in implementation costs. If in-ground production is as effective as air-pruned beds, we could prevent farmers from wasting time, money, and energy making air-prune beds. Contrastingly, if production in air-pruned beds yields significantly larger plants, it may justify the overhead. Data on root vigor and plant size will be collected. The outcomes will inform best practices for tree production and add over 1,000 trees to the Detroit landscape. This project will create income opportunities and models for farmers to play a role in meeting local tree demand.

The outcomes are:

• Explore the effectiveness of nursery practices in growing trees from seed in an urban setting
• Document the costs, skills, and labor required for managing a small nursery
• Gauge the potential of urban farmers to grow trees in Detroit

We believe farmers will adopt nurseries to supply trees to local buyers. Success looks like a system of farmers growing trees to meet local demand. Trees grown by farmers will be planted in the city, enhance the environment, and boost local food production. Different farms could specialize in other species or growth stages (seedlings, saplings, small trees, etc.)