We're tackling a touchy subject in this article; how to grow Azalea and Rhododendrons in Chicago.
In others words, how to keep them alive.
There has been some healthy debate around here about just how to explain to people the truth about planting these exceptionally beautiful shrubs. Some of us believe that planting a "Rhody" should only be done by experienced professionals.
Some experts feel strongly that professional site selection and the perfect soil amendment is the only way to ensure these shrubs grow well in the landscape.
But we disagree. At our garden center, we sell hundreds of azalea and rhododendron every year, without any problems. We will plant them for you, of course but I have seen thousands of customers successfully plant these colorful shrubs.
This article is going to explain exactly how we recommend choosing the variety, site location and soil amendments to ensure your plants thrive.
Choosing the Right Variety of Rhododendron and Azalea
We're not in the business of selling plants that die. And after selling and planting these shrubs for almost 50 years now, we simply know what works. You can probably buy these plants, anywhere, but here at The Barn, we are invested in your success.
We pick the varieties we carry carefully, ensuring each variety is proven to thrive in this climate. Cultivars are chosen for beauty and reliability.
Our Azalea Varieties Stocked for 2018
Our Rhododendron Varieties for 2018
Choosing the Right Site for Rhododendron and Azalea
Choose an East facing location or any location that will receive afternoon shade. Rhody's and Azalea need some shade in summer and protection from winter winds. A sunny, eastern exposure is best. The harsh afternoon sun of summer can be too hot and in the winter, the lack of water, combined with winter sun, dry them out. Excessive winds can also cause the shrub to die.
Rhododendron and Azalea tend to be understory plants in their native habitats. They receive shade from trees overhead and grow on slopes that receive some, but not too much shade. The slopes give good drainage, the abundance of leaf litter from the forest give them a moist and acidic soil that still gets plenty of airflow within it.
No matter how much you love Rhododendrons and Azalea, we do not recommend you plant them on the south side of your home. If you have a hot, full sun area, read this article on the best shrubs for full sun landscapes.
Amending the Soil: Planting the Rhododendron and Azalea
These plants will struggle in heavy clay or high PH soils (alkaline), both of which are common in our area. To offset the natural soil conditions we recommend that you elevate the planting and amend the soil. Planting an Azalea or Rhododendron in the regular soil of your yard is NOT recommended and will certainly lead to failure. Bad drainage, or wet feet, as we call roots that are submerged in too much water, will kill the shrub.
Whenever planting shrubs or any plant that requires good drainage, the wider you can dig the hole, the better your chances for success will be. This gives you more room for soil amendments that will improve the drainage and encourage roots to leave the planting hole.
Add a generous amount of soil amendments to improve drainage. Peat moss, leaf compost and other organic matter should make up at least 50% of the back fill of the planting. We have an excellent all-in-one soil amendment called One Step Soil Conditioner that is perfect for plants that require drainage or heavy soils.
One Step contains a plethora of ingredients that includes: pine bark fines, compost, leaf mulch, hardwood fines, iron sulfate (helps acidify soil), blue chip (maintains nitrogen availability as pine fines break down), gypsum (breaks up clay), and Mycorrhizae, which is a beneficial microbe that assists the roots with nutrient exchange.
Soil Acidity for Rhododendron and Azalea
Soil acidity, or lack thereof, is needs to be dealt with when planting.
Plants require two "types" of nutrients to be healthy.
1. The first are macronutrients; nitrogen, phosphorous, and potassium. This is the NPK or the three numbers displayed on most fertilizers. Macronutrients are more easily taken up as the pH moves toward the alkaline side of the pH scale. Plants also require micronutrients, however. These include iron, manganese, and zinc among others.
2. Micronutrients are more easily taken up in acidic soil. Too acidic and too alkaline of soils not only prohibit the availability of the opposite nutrients, but can actually lead to nutrient toxicity, or taking up too much of one type of nutrient.
The key to acidifying your soil is go slow. Adding elemental sulfur can take about 2-3 weeks to make any change to soil acidity. Yearly applications of Ironite can slowly improve soil acidity (it has 20% elemental sulfur) while also providing ready-to-uptake micronutrients that are normally only available in acidic soils.
Spray with Wilt-Stop in the fall and remember to generously water them before the first freeze. A second Wilt-Stop application can be applied in February or late-winter/early-spring when the ground is still frozen but temperatures begin to rise.
Enjoying your Blooms for Years to Come
In conclusion, Azalea and Rhododendron are two of the loveliest blooming shrubs you can add to a landscape. There are few comparisons in terms of the amazing color and ruffly texture. Even the waxy leaved foliage is a winner.
If you are willing to do the work to plant them correctly, care for them and have the ideal location, we recommend you give them a try.
And if not, we have almost 10 acres of other choices and I would be happy to provide some suggestions for alternatives to Rhododendron and Azalea.