Whether you receive bare-root roses from a mail order catalogue in the spring or buy your roses in a container during the growing season, there are a few simple guidelines for planting. But gardening is about trial and error; it's always important to see what works best in your own garden.
Site Selection and Preparation
Roses like full sun. They do best with 6 to 8 hours of direct sun a day. Some roses are described as shade tolerant. For a rose, shade tolerant usually means it will grow in 4 to 6 hours of sun.
Roses like morning sun whenever possible. Morning sun burns the dew off the roses and makes them less likely to suffer from mildew and other diseases. However, afternoon sun tends to be stronger than morning sun so, if you are only able to provide the rose with a half day of sun, choose the afternoon over the morning.
Roses don't like windy, exposed sites. On the other hand, they like good air circulation. Don't place them too close to a wall or a fence (a minimum of 4 inches), unless you are planting a climbing rose. Good air circulation prevents disease.
Roses don't like to be waterlogged; they like good drainage. When planting a rose in your garden, pay attention to the condition of the site, particularly in winter and spring.
Clear the area of perennial weeds.
In general, amend the soil by adding an equal amount of compost and really, old, farmyard manure (if you can find it). If you are gardening in heavy clay, make sure to amend your soil with plenty of organic matter.
Roses prefer to grow in soil with a pH between 6 and 6.5. If your soil is too acidic, you can add lime. If it's too alkaline, you can add gypsum (hydrated calcium sulfate).
Avoid planting roses in areas where roses have previously grown. If the old roses had any root diseases, they will still be in the soil. If you're planting a rose in an area that had roses, dig out a 2-foot by 2-foot space and replace with a fresh mix of topsoil and compost.
Roses are generally grafted onto root stock. The point where the rose is grafted onto the stock is called the bud union. This is a bulbous knot just above the roots of the plant. In this climate (New York metro area), it's best to plant your roses 2 to 3 inches below soil level. If the plant dies back over the winter, it will have a chance to re-sprout from the base below ground. The buried 2 to 3 inches of the rose stem will eventually root, and the rose will have its own roots as well as those of the root stock.
There are different philosophies of pruning roses after planting. Pick the one that suits your style of gardening and experiment with what works best for you. Some experts say that it's unnecessary to prune bare-root roses back hard when planted. Rather, do a formative pruning where the unhealthy branches are removed and the healthy stems are cut back to an outward-facing bud. Other experts advise an initial hard prune. They recommend that bush roses be pruned back to 5 to 6 inches from the crown (the part of the plant where the stems and the roots meet), leaving 3 to 4 buds on each branch. Climbing roses should be cut back to 12 inches from the crown, unless it is a sport of a Hybrid Tea or Noisette rose; pruning these roses could cause them to revert back to their original bush form.
If you cannot plant a bare-root rose within 24 hours of receiving it, heel it in by digging a small trench, laying the rose at a 45-degree angle and placing its roots below ground. Shovel some soil over it and water well. You can leave the rose in the trench for up to a week, or you can keep it moist in a cool, dark place (e.g. a garage or potting shed) for a few days.
When planting a bare-root rose, soak the plant (up to the bud union) in a tub of lukewarm water overnight to hydrate the rose. Using a sharp knife or a pair of pruners, cut back any damaged roots to just above the damaged part. If the roots are long, you can shorten them so they're easier to plant.
Do not plant your rose in soil that is too wet. Wet soil will form clods as you dig, and it is difficult for roots to grow in compacted soil. Clods also create air pockets in which roots can dry out and die.
Dig a large enough hole so that the roots can spread out.
Amend the soil with compost or aged cow manure. Add the organic matter to the backfill (the soil you have just dug up).
Mound up the soil in the middle of the hole, to the size of a softball. The mound forms a cone that the root system can spread over.
Spread roots out as evenly as possible over the mound. Add some soil into the hole. Lift the plant up and down just a little, to help the soil trickle in between the roots. Fill the entire hole and make sure you firm the ground around the plant.
Remove all thin, spindly branches so that you are left with a framework of strong, healthy branches.
Make your pruning cuts above a strong outward-facing bud. When pruning your rose, remember that roses do best when the center of the plant is open, allowing space for air circulation.
Bare-root roses initially need to put all their energy into root growth. Since they have a compromised root system, they are vulnerable to drying out from sun and wind immediately after planting. Hill up soil around the base of the rose to keep it protected. Just the top of the canes should be sticking out. Pull the soil back from the stems when you see the buds on the rose start to break and it begins to leaf out and grow.
Water your roses well.
Dig a large hole that is the depth of the container (or slightly deeper, if it's grafted) and twice as wide and prepare the soil by mixing an equal amount of compost into the backfill (the soil you just dug up).
Remove the rose from the container by cradling the rose's base (the soil around the base of the stem) with your hand and tipping the pot upside down.
If the rose is pot-bound, take a pocket knife and slice through the root ball surface in several places around the root ball. Tease out some of the roots to loosen them.
Set the plant in the hole so that the bud union is at least 2 inches below the surface. If you have purchased a rose that has not been grafted, plant the rose at the same level that it was growing in the pot.
Fill in the hole with the topsoil/compost mixture and water well.
Prune the roses back so that the top growth is in proportion to the root ball. Cut off any flower buds that would drain the plant of energy needed for root growth. A severe pruning is also possible at this time.
Container roses can be planted at any time during the growing season, but it's best to plant them in early spring or in the fall one month before the first severe frost.
Climbing and rambling roses will need some extra preparation to train them to the upright support you have provided for them. Planting a climber against a wall encourages upright growth. The roots should always be kept well away from the base of the wall as this is often a very dry area. Lean the stems in towards the wall, fan them out, and tie onto a support with twine.
To train a climbing rose, simply fan out the stems and tie them loosely into place on a fence or wall. The closer the stems are to horizontal, the more flowering shoots they will produce. Remove some of the shorter, twiggier stems at the base of the plant. This will help to create a taller climber more quickly by concentrating the plant's energy into the stronger stems.
Ongoing Care Tips
Fertilize roses each month through September for increased quality and quantity. A well balanced food (such as 20-20-20) works well. Roses also love Epsom salts (Magnesium sulfate) so sprinkle 1 cup around the base of each plant.
Practise deadheading. Cut spent flowers ½" above a set of 5 leaves.
Carefully prune hybrid tea roses in spring to about 3 to 7 outward facing buds per cane. Remove crossing branches, crowded growth, spindly branches and dead wood to the ground.
Protect against black spot and other fungal diseases when the leaves are fully opened. Use the Cornell formula and apply to foliage weekly and after each rain (Cornell formula: mix 3 TSP baking soda with 2 ½ TBSP of light horticultural oil into 1 gallon of water. Mix and apply as a spray.)