Autumn blooms: Mastering fall succession planting for a colorful garden
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AMERICAN FALLS — As the days grow shorter and colder, does your flower garden lose its vibrancy?
Succession planting is a technique used by vegetable gardeners to provide an offset of harvest for their crops. This same technique can be applied to flower gardens to extend the growing season, attract pollinators and keep gardens full even when temperatures drop.
Understanding fall succession planting
Fall succession planting extends bloom times, stagger flowering periods, maximizes garden space and facilitates flexibility and experimentation. This technique involves researching plant bloom times and either transplanting at staggered intervals, sowing seeds at various times or selecting species that have naturally different bloom times.
By understanding when the flowers are expected to bloom, you can create a schedule of blooms that will supply a steady supply of blooms throughout the fall, rather than a short burst of color that quickly fades. Once summer-blooming plants finish their cycle, garden space can be maximized by planting new plants to replace those spent blooms, keeping your garden diverse and dynamic.
Planning your fall floral succession
Planning begins with knowing your frost dates.
The frost-free growing period can be determined by finding the average last spring frost date and the average first fall frost date. This period between first spring frost and first fall frost allows for the calculation of optimal planting times for all flowers for the growing season.
The next step of planning is to choose suitable flowers. Flowers that will flourish in cooler temperatures and have varying bloom times will provide a diverse selection of plants and ensure a continuous display of color. Some fall friendly-flowers to consider include:
- Annuals: Ageratum, Amaranth, Celosia, Cosmos, Gomphrena, Marigolds, Ornamental Peppers, Scabiosa, Snapdragon, Statice, Strawflower, Sunflower, Zinnia
- Perennials: Asters, Black-Eyes Susans, Chrysanthemums, Ornamental Cabbage, Pansies, Violas
Resources such as the Bureau of Land Management (BLM) provide valuable plant growth information — including light requirements, water usage, pollinator attractors, seasonal interest, USDA zone and even mature heights. For instance, “Technical Reference 1730-3” focuses on using native plants for landscaping in the Intermountain regions. Native plants are a great candidate for fall succession planting due to their adaptability to local fall conditions.
Dividing the garden into sections or planting blocks provides an effective planting strategy. By planting each section two to three weeks apart, continuous blooms will continue to flow. Some flowers can be directly sown into the garden. Others may require starting indoors as seedlings and then being transplanted later — especially those sensitive to summer heat. The cool-loving plants may go dormant if planted when it is too hot or may not produce as expected because of heat stress. Researching and considering the needs of each flower variety is crucial to ensuring a bountiful flower yield.
While selecting the plants, consider their heights as well to provide a layered look. Combining tall-, medium- and low-growing varieties will make a tiered look while providing color at different heights and attracting diverse pollinators.
For example, using a Black-Eyed Susan (about one to three feet tall) as the tall plant and pansies or violas (four to eight inches tall) as the low varieties gives a great pop effect at various levels. None of these rules are hard and fast, so you can modify the plan to only have two layers or include more if the space is available.
Tips for success
Choosing fast-growing flowers, like sunflowers, in multiple succession every 10-14 days, will ensure continuous supply of blooms while also providing perspective on the soil and light conditions of your garden. Monitoring how the varieties do in certain locations can help determine if the soil needs to be amended or if the conditions are correct for certain plants.
Maintenance of the plants blooms by deadheading and cutting back regularly can help encourage a fresh flush of growth and can also potentially extend their bloom time without additional planting.
There are several fall succession planting guides online that can be utilized to help develop a plan instead of starting from scratch. These guides may need to be slightly modified for your region but provide valuable information related to plant types, growing recommendations and planting tips. For example, Johnny’s Selected Seeds offers examples of several species that can be adapted for your location based on first and last frost dates.
Developing a succession planting plan and schedule for your flowers’ blooms will keep your garden blooming and looking beautiful well into the cold, fall season.
In conclusion, a great benefit about fall succession planting is you can experiment as you like and find out what works and looks best for your garden.
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