Basic Rhododendron Needs
Rhododendrons have a few basic needs to ensure they will grow well. They can grow almost anywhere given appropriate environment, but thrive in the Pacific Northwest of the United States where Rainier Rhododendrons is located. Rhododendrons do best under the following conditions:
Acidic Soil A rhododendron plant will grow best in soil that is course enough to provide needed oxygen to the roots. An adic medium (ph 4-6) works best. If your soil is not acidic you can add peat, sulfur, or ferrous sulfate to the soil. You can have your soil tested at some univerisities and garden centers, or buy a pH test kit at most nurseries, or hardware stores. Rainier Rhododendrons has a mixture we use for our rhododendrons available for sale (while quantities last) with a plant purchase.
Lots of Moisture Rhododendrons do best with a constant supply of moisture. That's why they grow well in the Pacific Northwest! However even in the Pacific Northwest during the summer you will want to give plants additional water. Rainier Rhododendrons waters our plants just about every day throughout the summer months. In drier climates you may need to water plants even more often.
No Stagnant Water Don't let the roots of your rhododendron sit in stagnant water. The roots need oxygen and well drained soil. That's why a rhododendron in the cool, wet Northwest with course, oxygenated soil will survive while a plant in a wet spot in the Southeast's heavy rains would have problems.
Sun / Shade Most rhododendrons prefer some shade but look at the information for the specific plant you are purchasing. Our web site tells you which plants prefer shade and which can handle the sun.
Hardiness When you purchase a rhododendron check the "hardiness" of the plant which is basically the lowest temperature that plant can stand. Make sure that you pick a plant that can withstand the lowest temperature in your area.
Fertilization Rhododendrons will need some fertilization to flower best. Additionally a well-fertilized plant will withstand more cold. Rhododendron plants do well with a combination of nitrogen, phosphate and potash in a 10-6-4 ratio. Some recommendations say apply fertilize once sometime in April-May and again in June-July.