by Mark Whitelaw This is part two in Mark's three part series on Landscaping With Roses. The other articles in this series are: Landscaping with Roses: Design Decisions.Landscaping with Roses: Selecting the Rose.
Once the design "whys" and "hows" have been answered, the next order of business is to determine the best landscape location for siting roses in the landscape - the "where."
Locating the roses is fundamentally a design decision dependent upon the gardener's landscape intentions and driven by the three fundamental needs for all roses - plenty of sun, plenty of air, and plenty of nutrient availability.
Roses need sun. Lots of sun! Normally, not less than six hours of sun! With few exceptions, roses will not bloom regularly, remain disease resistant, nor grow to their "programmed" size without a minimum of six hours of sun. Whether designing roses into a specified, monocultural area such as a rose garden or distributing them in and around the landscape, care must be taken to design the landscape so that the roses will receive the maximum amount of sun available.
If planting them in groups, space the taller roses behind so they will not shade their smaller companions. If planting them among other landscape ornamentals, locate them well away from tall-growing shrubs or perennials. Keep them to the south-facing side of tall fences, walls or tall-growing shrubs. If planted near wooded areas, watch the sun-shade patterns of the trees to ensure the maximum amount of direct sun. And remember: As the seasons change, so do the shade patterns. Planting a rose on a north-facing wall will keep it in the shade for most of the year. Hint: Place a few stakes in your proposed planting areas and time the amount of direct sun the stakes receive during a typical spring or summer day.
In the drawing, note the three roses (the "starburst" graphic). The rose on the left is shaded on both the east and west side by dense shrubbery. The only sun it will receive is when the sun is directly overhead - the worst sun of the day.
The rose on the right (the east) receives morning sun - the best sun of the day. On an average day, it will receive about six hours of sun. Planted to the east and in front of this rose are low growing perennials. Taller perennials are kept behind the rose, along the wall.
The rose in front of the shrub receives sun for the entire day. Companion plantings are kept low and in front of the rose. This rose will be the healthiest, bloom the best and grow to its designated size.
Roses also require good air circulation. The more circulation, the less likely disease and insects will invade. Care should be taken when designing roses into the landscape which are next to solid structures like fences, buildings or even large, dense shrubbery.
In the drawing, the rose on the left is planted too close to the wall and between two, taller-growing shrubs. Air circulation around the rose is minimal except on the windiest of days. Fungal diseases can be expected to attack this rose in the spring and fall, and reflected heat will cause stress on the rose during summer - ensuring insect attacks.
The rose on the right is planted away from the wall. As a rule of thumb, plant roses so that at their mature size the foliage will remain at least two feet (60 cm) from a solid wall, especially if that wall is south-facing. Low growing companion plantings are place in front of and to one side of the rose to ensure sufficient air circulation is maintained. Taller perennials are placed behind the rose to help reduce reflected heat during hot summer months.
The rose in the center, in front of the shrub, receives the best air circulation and least heat reflection from the wall. Again, any companion plantings are kept low, in front of and to the sides of the rose.
Roses need access to all their required nutrients. These include water, deep organically-improved soil, and an occasional supplemental fertilization.
Design the landscape to ensure a water source is nearby. Depending on the type of rose and consequently its bloom frequency and leaf size and structure, roses will need approximately 24 - 30 gallons of water per week just to survive during a hot summer. Too little water will cause heat stress, disfigurement, and subsequent insect invasion. Too little water will also reduce leaching of harmful salts that can build up in the soil from fertilizers. And too little water can reduce the metabolization of nutrients in the soil. Water is a must!
The planting area where the roses are to be placed must be deep, improved with organic materials and well-drained. All to often, gardeners plant a rose in partially improved soil only to have the rose die a few months later because the drainage was poor or the subsoil was devoid of nutrients. As a rule of thumb, roses will need 2 - 3 ft. (60-90 cm) of root space both down and around the rose. If necessary, an elevated planting bed should be considered. And organic materials should be chosen suitable to the soil conditions in the landscape. Not only do they represent potential nitrogen, but they help retain soil moisture as well. A quality soil test performed before the incorporation of organic materials will assist in determining which materials to add.
Occasional fertilization is a deliberately vague term. Depending on the fertilization method, access to the rose may be necessary anywhere from twice a month to twice a year. In the drawing, the front rose has the best accessibility for supplemental fertilization.
One more note: Regardless of the fertilization method chosen, overfertilization should be avoided. The rose can metabolize only so many nutrients, depending on water availability, root development, soil temperature and type of nutrient. Excess nutrients can leach into subsoil water tables or run off into streams and lakes, causing hypereutrophication and subsequent pollution. Some nutrients may lock up in the soil and create an imbalance in soil chemistry.
The next article in this series will discuss which rose to select for designing the landscape... because not every landscape has an ideal "where" in which to plant a rose.