Glorious Rhododendrons
Gardening Tips for May
- Plant an herb garden in a container near the kitchen door for convenient fresh spices like basil, oregano, parsley, and sage.
- Potatoes can still be planted this month. Choose red, white, yellow, and russet varieties for different uses and flavors.
- Ivy geraniums make wonderful hanging baskets for partially shaded spots, blooming all summer.
- Tomatoes are the most popular summer vegetable. Select from the many varieties available now for home-grown flavor.
- Mulch blueberry plants with aged sawdust and feed with cottonseed meal or an acid fertilizer.
Growing Rhododendrons
There are few sights more beautiful in the plant world than a mature rhododendron covered with large, rounded trusses of bright, colorful flowers. These large shrubs can enclose a shade garden and provide spring blooms.
The rhododendron family includes over 900 species, ranging from ground-cover shrublets with needlelike leaves to large-leafed tree types. While most are native to eastern Asia—from Siberia to New Guinea—they also grow naturally in Appalachia and coastal forests.
Hybridization over the past century has produced tough, adaptable, and easy-to-propagate rhododendrons with attractive foliage, vigorous growth, and large, colorful flower clusters.
Soil and Planting Requirements
- Rhododendrons are shallow-rooted and need moisture and oxygen in the root area.
- They thrive in soil rich in organic matter with good drainage. In poorly drained sites, build a raised bed or mound to elevate the rootball above ground level.
- Plant no deeper than the container depth—shallow planting is better than too deep.
- Acidic soil (pH 5.5–6.0) is essential. Test soil pH and amend with sulfur if needed.
- Fertilize once or twice in spring with an acid fertilizer, though established plants may need little to none.
Light and Watering Needs
- Rhododendrons need some sunlight to bloom—ideally 3–4 hours of morning sun or filtered light all day.
- Insufficient sunlight can lead to poor blooming and leggy growth.
- Water regularly through summer months.
- Minimize cultivation around shallow roots; use mulch (sawdust, bark, straw) to control weeds, retain moisture, and regulate soil temperature.
Colors and Varieties
Rhododendrons bloom in a range of colors, from pure white, pink, and lavender to bright reds and purples. A few varieties also offer yellow or cream hues, making them a vibrant addition to spring gardens.