When talking about September, it is true that it’s when your perennials may start to looks a little tired. However, it is also the most important time when you can do a simple task that will elevate your garden to the next level for spring.
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Check PriceMany gardeners ignore the month of October even though their plants are asking to be divided. The following spring, plants are stressed and struggling and can't understand why their divided perennials look sad and take forever to recover.
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This is what the experts say: Divisions made in September align with your plants' natural cycles. Over the summer your perennials have spent time building energy reserves and are now ready to use that energy to establish new root systems before the cold.
Indicators for dividing your perennials
Your plants have been telling you what they want all summer. Outer growth with dead centers, smaller blooms than in past seasons, and flowers that fade quickly scream 'divide me now.' These signals tell you that your perennials aren't dying, they're gearing up to multiply!
The real magic takes place underground. Clumps this old have nutrient depletion from their immediate soil zones and over-crowded root systems with congestion due to competition. Division is not just maintenance – it's plant multiplication turning one struggling parent into five thriving offspring.
1. Daylilies: Champions of Multiplication
Though daylilies form a strong clump, indicating a healthy plant, it can mean the opposite when the centre of the clump becomes weak. This means the plant is using its energy to grow more shoots to the edges of the clump where the soil is better for nutrient uptake. This is a sign that the clump is becoming overcrowded. To rejuvenate the plant, remove the complete clump and separate the crowns with a sharp spade. In order to successfully grow each new crown in a new location, each crown division must have a minimum of 3 shoots and a healthy root system.
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2. Hostas: Shade Garden Gold
After five years hostas tend to show signs of stress as the self-choking plant produces fewer flowers and smaller leaves even when the growing conditions are ideal. Dividing hostas in September is a great way to ensure they develop healthy and robust root systems before the ground freezes. This promotes healthier and fuller growth in the spring.
3. Irises: Rhizome Renewal
Every year, Iris rhizomes extend further, leaving behind sections that will eventually decay and become infested by boring insects. When you notice a drop in flower production and soft patches in older rhizomes, it’s time to divide the plant. Healthy rhizomes should be cut into pieces with firm growth and robust roots. Replant these sections with the tops slightly above the soil.
4. Coneflowers: Self-seeding and Spreading
Purple coneflowers grow in large clumps: while this looks healthy, in reality, it hampers the vigor of individual plants. If your flowers are getting smaller with shorter stems, and you are providing good care, the plants are stifling themselves. Dividing perennials in September allows space for roots to spread, leading to larger blooms and stout stems.
5. Peonies: Worth the Investment
Peonies dislike being disturbed but large established clumps that have failed to bloom for two years need some intervention. You want to create divisions as late as possible in September to give maximum time to these deep-rooted perennials to establish themselves before winter! For each division to be successful, it needs at least three growth buds, and depth is critical – if you plant too deep, you can expect to wait years for blooms.
6. Disease Prevention for Garden Phlox
Clumping dense phlox can lead to the development of powdery mildew and other fungal issues. Dividing the clumps will aid with air circulation and produce younger and more vigorous plants. Look for clumps that have declining center and weaker flower production as strong as your divisional signals.
7. Shasta Daisies: Continuous Bloomers
Due to the tightly compacted groups, Shasta daisies can't support the proper blooming of their flowers. A loss in flower production and a congested plant means it's time for division to reinvigorate the entire system. Every division should have several shoots alongside a strong root ball.
8. Astilbe: Iubitori ai Umidității care se Înmulțesc
The crowns of Astilbe plants get bigger each year. However, the old center shoots will eventually become woody and unproductive. When the bloom size and quantity start to diminish, it’s time to divide them. Astilbe are stress-free during the summer which is why September is a good month to divide them because of the moisture.
9. Bee Balm: Spreads Aggressively
Bee balm sends runners under the soil to spread and form large colonies. If the center of bee balm plant patch is getting sparse while the edges are busier, then dividing the patch will help control the spread, while also invigorating the exhausted plants. Each division will need both shoots and roots, for the division to be established successfully.
The September Advantage
As air temperatures lower, soil temperatures remain warm, and this promotes excellent conditions for root development. This means when planting in September, vigorous root systems will be developed instead of the plants supporting unwanted top growth. In this way, the plants will be healthier and stronger for the following year.
Water multiple times and apply a thin layer of mulch to keep the soil from heaving during freeze-thaw cycles. By spring, instead of one tired specimen, you'll have a number of thriving plants, ready to take on the world!
