Summer planting of roses can be a little tricky due to the heat, dry or very humid conditions associated with the season. A few timing tricks, plenty of water and good rose cultivation practices can make summer as successful a planting season as any other. Bare root roses should be planted in spring or early summer as soon as you receive them so that the canes do not dry out and become damaged. Container-grown roses can be planted through the spring, summer and fall in most climates and can also be planted in winter in temperate climates.
Select a planting site with a full sun exposure proving at least 6 hours of bright sunlight daily. Prepare a planting bed of nutrient-rich and well-drained soil tilled up at least to the depth of your rose roots. Amend the soil with a few pounds of quality compost to boost the quality if need be and mix in well. Dig a hole twice the diameter of the rose root ball or bare canes and at least as deep.
Plant your rose in the early morning or in the late afternoon to avoid the peak heat and sun of the day. Slide the rose out of its container gently and loosen the soil around the exterior roots lightly. Place the rose in the hole and place some of the amended soil under the plant to support the roots and bring the top of the root ball level with the surrounding soil. Back fill the loose soil around the roots and press down gently to collapse any air pockets.
Create a watering moat several feet in diameter and at least 3 inches high with the remaining soil. Fill the moat carefully with water and allow the water to percolate into the soil before filling the moat a second time. Continue to water your newly planted rose every 3 to 5 days until well established. Scale back to deep watering once per week going into the fall.
Feed your rose with an organic rose food after planting and several times per year thereafter according to product label directions. Select something like Rose-tone, fish emulsion or kelp extract for best effect.
Mulch around the base of your rose with 2 to 3 inches of organic material such as shredded bark, compost or cocoa bean hulls. Leave a 5-inch-diameter collar around the trunk of the rose where there is no mulch to avoid wicking moisture and rot. Continue the mulch 6 to 12 inches past the drip line of the rose. Mulch will hold moisture in the soil and insulate the roots from the summer heat.