Planting near concrete foundations or other concrete materials should be avoided because concrete creates alkaline conditions (pH 6 or higher) that interfere with the healthy growth of rhododendrons and azaleas. People often use aluminum sulfate to lower soil pH, i.e. make it more acidic, for hydrangea growth. The use of aluminum sulphate for acidification of rhododendron soils is not recommended as aluminum is toxic to rhododendron and azalea roots. To lower the pH of the soil, use wet sulfur or iron sulfate. Such soil with a sand component will always drain well and give excellent long-term results. Sand, gravelly soil, or well-drained clay are more important to Rhodo`s success than organic matter. You heard it here! Good soil conditions are very important. (For more information, see Soil conditions.) Rhododendrons are acidic plants. As such, they work best when the soil is acidic (with a pH between 4.5 and 6.0).
You need a well-drained soil with an abundance of organic matter. Rhododendron and azalea roots also need oxygen for healthy growth. Many materials can be used to improve the soil. Compost or decomposed pine bark is very effective. Heavy clay soils collect and store water, so it is recommended to plant rhododendrons and azaleas above the base clay soil in a mound with desirable soil. (See screenshot below.) If you dig a hole in heavy soil and fill it with a mixture of light soil, you may want to create a bucket with a lot of water. Soil pH can be easily measured with a soil analysis kit available in garden centers. Alternatively, the RHS offers a comprehensive soil testing service. If you need to prepare a new bed of rhododendrons and lower the soil pH, apply 1.5 pounds of elemental sulfur or 3.5 pounds of iron sulfate per 100 square feet to lower the pH by 1 point. Ferrous sulfate acts faster than elemental sulfur, but costs more. 7) Say, “But the soil mixture in the pot I bought it in was rich organic soil.” ALL RIGHT.
But it was in a nursery, with controlled irrigation and chemicals to keep diseases at bay. FRESH organic matter in the form of bark, etc. in pots. is excellent for the cultivation of Rhodes for the grower, for a short time until this bark collapses. But that`s not good for long-term results. Unfortunately, what is good for the producer may not be good for you, the customer. At Eastern Plant, our soil mix is partly sand, partly real dirt from the forest and sometimes perlite (volcanic rock) Our plants see dirt from the real world so they can adapt. The analogy is of a child playing outside in the woods, building a better immune system than a child staying inside.
Rhodes and really any plant grown in real conditions are MUCH MORE RESISTANT AND RESISTANT. See the image of the soil below and its stony and crumbly texture. You may think (and books often say so) that it`s great for all plants, especially Rhodes. Experts say, “It`s so fragile and perfect.” NO and it`s deadly for Rhodes. This stony and crumbly texture comes from earthworm casts. It “might” be good for tomatoes, lilacs and many other plants, but it is deadly over time for Rhodes and his relatives. In addition, the “earthworm soil” tends not to be acidic enough for these plants. Walk on this earthworm soil several times and it will become compacted earth. Thanks to commentator Deborah Banks for mentioning how earthworms actually destroy natural leaf litter which is the perfect mulch; See the rest of their comments below. Eastern Plant, the best rhododendrons in the eastern United States! Grown outdoors in Maine`s harsh climate. Harder, harder, just better! Aeration: Aeration is important for healthy growth of rhododendrons and azaleas. Beneficial microorganisms in soils need air for respiration and metabolism.
Vital microbial and fleeting activities, such as degradation of organic matter that makes nutrients available to plants, nitrification and beneficial mycorrhizal associations, depend on oxygen in the soil. Poor aeration leads to the development of toxins in the soil. Plants in heavy soils with poor aeration often become chlorotic due to malnutrition. To improve soil aeration, organic matter is the best supplement, compost being an excellent choice. Soil bacteria acting on compost produce humus that combines with soil particles – which separates densely packed particles; improves drainage and allows the fine roots of rhododendrons to penetrate the soil more easily. In coarse sandy soils, it settles in large interstitial spaces and acts like a sponge, so that the soil remains moist longer. It is not recommended to change heavy clay soils. Eventually, the organic supplements come off and the soil returns to its original state. As mentioned above, in gardens with heavy clay soil, the best approach to growing rhododendrons and azaleas is to use a raised bed on the domestic floor. TEACH.
A TRUE LIFE EXPERIENCE FOR ME All of the above also comes from a personal story and a learning experience I had the hard way to return to New Jersey when I started. I brought compost trucks AND filled the yard with them. Bought tons of Rhodes. They worked well for a year, and then I noticed that Rhodes` root systems had become smaller. In addition, I had to water all the time. Then I saw the explosion of the earthworm. (I haven`t connected these dots yet) Why my Rhodes doesn`t prosper, no one had the answer. I then started inserting sand into the compost soil and mixing it. It certainly helped, but it still wasn`t right.
It was necessary to connect the dots. and years of observation to get the answers. I want to spare you this time! In warm climates, root rot thrives in moist soil and can kill rhododendrons and azaleas.