The Field

Maybe it can be attributed to our agrarian heritage here in the upper Midwest, but in your Design-Build PPN co-chairs’ world, plant material – and we mean great plant material – is critical to the impact and success of our projects. Knowing who to source from and the quality of their products are critical to our happiness and to your client’s satisfaction. So we thought it might be good to dig into this a bit and share some of our experiences. As always, we encourage your comments about what has worked well for you in your practice.

Plant material is available everywhere. From huge nationwide wholesale growers, to “Ma & Pa” tree farms and specialty sources focusing on one category of plant material, the landscape architect’s choices are endless. When we are in “design mode,” it might be fair to say that we most likely already know who we will use to purchase our trees, shrubs, herbaceous plants, natives, aquatics, etc. Those potential sources carry the varieties being specified and they also may have the level of quality that best suits your project’s budget and meets (or exceeds) the expectations of you and your client.

Though the sources are many, there are some reasons to use discretion when sourcing your plant materials. Let’s look at some important characteristics of good growers and how to best select your nursery supplier partners:

1.  Buy local
Besides being the sustainable thing to do, getting your fresh dug trees and shrubs from a source with similar soil to that of your project’s site is very advantageous to getting your planting areas established quickly. Another reason to buy local is to see the material before ordering it. Many high end clients may also like to see the expensive plant specimens and hand select some of them. A good nursery grower will have the means of taking the landscape professional and their clients out into the growing fields for these important selections. This may involve a small mark-up on the wholesale price for this client tagging service, but other nurseries may not assess this charge if you are regular clients.

2.  Establish a solid relationship with your wholesale growers
Let them know what your expectations are or the level of quality you seek. Expect prompt customer service from them as to availability, harvest timing, trucking/delivery timetables, etc. Let them know your overall interest and enthusiasm for great plant materials. A good nursery representative will send you an email or a text to tell you about a special shipment they have received, or a photo of an unbelievably beautiful tree that needs a home. This kind of kindred spirit is huge!

They will also tell you that some of their perennials may have just been given a mid-season cut back instead of the being shipped with a great deal of floppy and disheveled top-growth. You can then tell your client that this cutting off of the flowers and top growth was the right thing to do for the plant’s sake at the time. Some growers will even ask you for thoughts on what plant types you often design with, what clients are asking for, and which plant varieties you would like to use that they aren’t currently carrying. They value our input as landscape architects and will often make serious efforts to expand their offerings.

3.  Know good from bad quality
To us as landscape architects and specifiers, it is all about appearances. Plant materials that are staged in tight rows at a grower’s holding yard can look fine in spring, but those same plants can look pretty nasty by the Fourth of July if they are not occasionally spaced for access to sunlight. Also, overhead watering of plants is a common procedure, especially with large inventories to maintain. There is a price to pay by mid-season though, when the deciduous plants could suffer from bacterial leaf spot from frequently moist foliage or a white appearance on the leaves with calcification from hard water.

For conservation of water and aiding in maintaining cleaner, more lustrous plants, many growers are moving toward drip irrigation – it makes a huge difference! And to take it a step further, running calculated, seasonally adjusted doses of nutrients through the drip systems (sometimes referred to as “ferti-gation”) creates night and day results in the end product.

4.  Nursery yard display
The other factor that seems to contribute to stored plant health and appearance is the way that the larger shrubs and trees are displayed in the nursery yard. Many growers are moving away from heeling their plants’ root-balls and containers into bark mulched environments. This type of storage may be cost effective, but after a lot of moisture and mulch build-up, the plants’ root systems are often dealing with constantly waterlogged conditions and possible pH readings detrimental to the health of that plant stock.

Many plant nurseries are moving to “above-ground” storage of these larger plant materials with a well-drained gravel substrate. This eliminates the waterlogged issues of the “soil and mulch” based holding yards, and the plants’ nutrient and moisture requirements can be carefully provided and adjusted. This gravel method also aids tremendously in getting equipment access to the large trees regardless of wet or dry weather. These measures are desirable in the eyes of the design-build landscape architect creating the opportunity to obtain attractive and healthy plants that are reliably available and accessible regardless of weather conditions, helping you keep your project’s timing on track.

5.  Know proper harvesting and plant handling procedures
As design-build landscape architects and practitioners, we purchase most plant materials on a wholesale basis which means that the growers do not have a warranty on the success of those plants once they roll off the nursery premises. Be sure that the plants are in properly sized containers or root balls. Also, be sure that the root flares of trees and the root crowns of smaller plants are at the proper finish height in their burlap, or in their containers.

With production advances from using wire basket tree digging equipment, or potting machines, the one-size fits all concept does not always work out too well. Tree root flares may be buried under six inches of soil, burlap, and twine, so extra care is needed to correct these conditions during the planting phase. Occasionally, there are differences in opinions from one supplier to the next as to how late in the season they will harvest certain species. Because they do not have to warranty the plants, you need to be very aware of when you are getting in the “danger zone” as far as timing goes. It is often your call to plant or not plant, but when you are close to the end of the best window to do the work, a reputable nursery will strongly discourage you and pass up a quick sale in favor of giving you the best advice.

It is often better to tell your client that a few select varieties might best be delayed until the following season for their installation, despite everyone’s hopes of wrapping that project up completely by year’s end. It’s a huge hit to your profitability to replace plants, so educate your clients about the seasonality of certain plant installations.

Also, insist on proper shipping practices from your vendors, or in some cases your own trucking staff. For instance, the burlap packaged plants should be in reasonably sound root-balls (without gaping tears in the burlap) and very importantly, they cannot be dropped when loaded or unloaded. Plants with wide branching should also be carefully tied in to minimize branch breakage, but not too tightly, as that can stretch bark and cambium tissue causing damage of its own. Loads on open trailers or trucks should be secured with a tarp before transport to prevent wind and sun damage during warm weather installations or shredded foliage from highway driving.

Finally, upon delivery and unloading of plant materials, it is very important to get someone started on watering them – immediately! During summertime installations, if at all possible, try to place the unloaded nursery stock in an area out of direct sunlight (under the filtered light of taller trees is great) just for the first few hours (even day or so), to help the plants acclimate to your projects exposure to sun and wind.

Whether it is shade trees, perennials, exotics, or natives, the design and installation of plant materials can be a spectacular enhancement to a landscape. We have found over the years that with solid vendor relationships and proper installation and handling methods, the opportunities to provide creatively designed and high quality plant installation work can be very profitable for your design-build practice.

by Chris Miracle, ASLA, and Tim Garland, ASLA, Design-Build PPN Co-Chairs