7 Tips for Extending the Bloom Times of Your Astilbe
Are you trying to get the most out of your Astilbe blooms this season? There are a few different actions you can take that will keep your Astilbe's blooms thriving. In this article, certified master gardener Laura Elsner shares her top tips for long-lasting Astilbe flowers in the garden.
Astilbes add beautiful texture and color to the garden. With their lacy leaves and richly colored plumes of flowers, astilbes will add drama to your garden.
Astilbes have a wide range of bloom times. It’s not like peony varieties that all bloom in late spring within a week or two of each other (give or take). Some astilbe varieties will bloom early in the season in the early-midsummer range. Then there are varieties that bloom later in the season, in the mid to late summer range.
So, once you once they start blooming, how can you keep their beautiful flowers blossoming all season long? There are actually a few different actions you can take that will prolong their beautiful blooms. Let’s dig a little deeper as I share my top tips for longer blooming astilbes this season and beyond!
Provide Enough Sunlight
You want to be growing your astilbes in the sunlight sweet spot. Too much sun and too little sun can affect the blooms on your astilbes. Part sun-part shade is the best place for astilbes.
Too much sun will fizzle out the flowers fast. If you do find your astilbes are getting too much sun and are fading fast, give them more water. Amending the soil so it can retain water while still being able to drain excess will help. A top dressing of compost will help achieve this.
While astilbes are touted as shade plants, they will not bloom in total shade. They need some sun for big full fluffy blooms. If you find your astilbes are struggling. They have spindly foliage and little to no blooms each year. Consider moving them to an area that receives more sun.
Provide Just Enough Water
Astilbes do require a medium amount of water. They will get brown tips on the foliage, and the blooms will be stunted if they don’t get enough water.
A deep watering once a week should suffice. If you have them planted in with hostas, they can be watered on the same schedule. I find mulching or planting ground covers (e.g., sweet woodruff or creeping Jenny) is a great way to retain moisture. Astilbes that are getting adequate water will bloom bigger and fuller.
On the flip side, too much water can be detrimental to your astilbes. They do not like being soggy. They will rot and die in constantly wet conditions. Make sure to evaluate the site before planting an astilbe. There can be soggy patches in a shade garden. Avoid playing astilbe in those areas.
Use Nutrient-Dense Soil
Soil is another factor to consider for beautiful, long-lasting astilbe blooms. I can’t stress this point enough. Soil is everything. Your garden is only as good as your soil. Of course, not all plants like the same soil. Astilbes like rich, loose, free-draining soil. They don’t like heavy clay soils or soil that is devoid of nutrients.
You can do a simple test to see if your soil is full of clay. Grab a handful of your soil and squeeze it in your palm. When you release, it should crumble and not hold its shape. Clay soil will stay in a ball. If your soil is clay, amend it with lots of compost and some peat moss or coconut coir.
Adding astilbe into an already healthy garden full of big beautiful hostas, brunnera, ferns, etc is a great way to ensure your astilbes will be going into good soil. These plants all like the same rich free draining soil.
Provide Protection from The Elements
I always find that plants do better when they’re together in a garden. Astilbes are no exception. Astilbes do best when they are part of a garden. Nestle then in and amongst other shade perennials and annuals.
They are not a great choice for lining driveways or out in open areas. If you provide a protected location for your astilbes the blooms will last longer. Keep them out of high wind and areas they can be pelted with rain and/or hail (if possible)
Stagger Varieties for Blooming Season
This is the big one when it comes to extending the astilbe season. It’s not so much about extending the blossoms on an individual plant, but instead planting different varieties of astilbes that bloom at different times of the season.
Astilbe varieties have widely varying bloom times. Some bloom in the late spring-early summer. Then some varieties bloom in mid-late summer.
Planting different varieties of astilbe with different bloom times is the best way to extend the bloom times of your astilbes. Once one variety starts to fade, the next variety will start blooming and take over.
To make it seem like your astilbes are blooming for a longer period, try planting varieties with similar colors, but bloom at different times. For instance, for red blooming astilbes, plant ‘Fanal’ for early summer blooms.
Then plant some later blooming ‘Burgundy Red’ astilbes in between. The differing bloom times will make it seem you have red astilbes blooming in your garden almost all summer.
In general, astilbe japonica are the early blooming astilbes. Astilbe chinensis blooms later in the season. Check the tags when purchasing a plant to make sure you are getting the bloom at the time you want. If you are dividing existing astilbes, take note of the period they bloom.
Skip the Deadheading
Astilbes don’t bloom again if you cut their flowers. I find their flowers still have interest and look good after they have bloomed. They have a dried quality that adds texture.
This will make it seem like your astilbes are in bloom for longer. Of course, this is a personal preference. If you don’t like the look of dried-out stalks, simply trim them off.
Overwinter When Necessary
Taking the time to prepare your astilbe for the winter will make sure you have healthy plants ready to emerge and bloom strong in the spring.
Astilbes don’t require much attention. They are generally considered low-maintenance perennials. The only thing to do in the fall to prepare your plants is to make sure they are watered and mulched.
Fall can be a dry time of year. Don’t let your astilbes go to sleep dry. Where I’m from my clients tend to turn their irrigation off before the ground freezes. This does not mean plants are done with water. Make sure to water plenty before that occurs. Aim for a long slow watering.
Adding a layer of mulch to the base of your astilbe will help keep the moisture in and keep them protected over winter. This can be as simple as piling leaves on them. I usually rake leaves off the lawn (to prevent mold in the spring) and then I will add those leaves into my garden over the winter.
Keeping your astilbe healthy is important for big, long-lasting blooms. But the big secret is layering varieties that have early and late bloom times. This will make your astilbes appear to be blooming from late spring all the way through late summer. These fluffy poufs of blooms are the perfect thing for adding texture and color into the shady areas of your garden.