Succession planting is a practical and high-yield approach to gardening that pays off especially well in Colorado, where elevation, short growing seasons, and rapidly changing weather demand flexibility and planning. This article explains what succession planting looks like in Colorado, with clear strategies, crop-specific schedules, soil and climate considerations, and actionable examples for Front Range, mountain, and Western Slope gardens.
Colorado gardeners face a particular set of constraints: variable last and first frost dates, wide elevation ranges, low humidity, intense sunlight, and often shallow or rocky soils. Succession planting mitigates these constraints by:
Extending harvest windows for popular crops.
Reducing risk from late frosts, heat waves, or pest outbreaks by not putting all seeds in at once.
Maximizing productivity in short seasons through multiple plantings of fast-maturing varieties.
Allowing relay use of beds so space is continuously productive.
Succession planting is not one-size-fits-all; it must be adapted to your local zone, microclimate (south-facing walls, thermal masses, wind breaks), and the crop choices you prioritize.
Before you plan succession plantings, determine:
Your average last spring frost and first fall frost (use local agricultural extension, weather station, or historic data).
Elevation: 3,200 to 5,300 feet on the Front Range, 7,000+ feet in mountain valleys, lower deserts on the Western Slope. Each elevation shifts the effective growing degree days dramatically.
Soil type and drainage: many Colorado soils are alkaline and clayey; raised beds and amendments are common solutions.
Sun exposure and wind patterns that influence day temperatures and nighttime lows.
Example reference points (adjust for your location): Front Range metro areas often have a frost-free season of roughly 120 to 160 days. Mountain valleys may have 60 to 100 truly reliable days.
Staggered sowing means planting the same vegetable at regular intervals so that harvest occurs over a longer period rather than all at once.
Cool-season crops (lettuce, spinach, radish): sow every 7 to 14 days.
Root vegetables (beets, carrots): sow every 2 to 3 weeks.
Bush beans and summer squash: sow every 10 to 21 days early in the season to extend production until fall or frost.
This approach is especially useful in Colorado because a heat wave can prematurely bolt cool crops; with staggered sowings, later plantings can replace early losses.
Relay planting overlaps crops in a bed: as one crop finishes, another is seeded or transplanted into the same space. For example, transplanting tomatoes into spaces between harvested early spinach or peas.
Relay planting examples:
After a spring pea harvest, immediately sow beans or cucumbers in the same row.
When early lettuce is harvested, seed quick-growing bush squash or transplant heat-loving peppers into cleared areas.
Relay planting requires soil fertility planning, add compost or side-dress to support the next crop.
Choose a mix of short- and long-maturity varieties so the patch matures at different times without extra sowing.
This method reduces sowing effort and still provides succession benefit.
Colorado can produce late-season harvests with the right crops and protection.
Plant kale, collards, and bok choy in mid- to late-summer for fall harvest.
Direct-seed spinach and overwintering garlic in late summer/fall.
Use row covers or cold frames to protect winter greens from early freezes and to extend harvest into late fall and sometimes winter.
A cold frame or cloche can add 2 to 6+ weeks of season depending on severity of winter.
Below are concrete schedules using days-to-maturity (DTM) as a guide. Adjust the intervals to your local frost dates.
Radishes (DTM 25-35): sow every 10 days in spring and again in late summer for fall baby radishes.
Lettuce (DTM 30-60 depending on variety): sow every 10-14 days; plant heat-resistant varieties for summer and shade with taller crops or row covers.
Spinach (DTM 30-45): sow every 2-3 weeks in spring and for fall plantings; bolt-prone in high heat, so aim for early spring and late summer.
Carrots (DTM 60-80): sow successions every 2-3 weeks to ensure continuous harvest; intercrop radishes to mark rows and harvest quickly.
Beets (DTM 50-65): sow every 3 weeks for steady harvest.
Peas (DTM 60-70): plant as early as soil can be worked; second planting 2-3 weeks later can prolong the harvest.
Bush beans (DTM 50-60): succession every 10-14 days until midsummer, then last sowing timed so pods mature before first fall frost.
Summer squash/cukes (DTM 50-60): sow transplants or seeds every 2-3 weeks for continuous production.
Tomatoes/peppers/eggplant: generally transplanted and not succession-seeded. Instead, stagger transplant dates or plant varieties with differing maturities; replace early plants with heat-tolerant late-season beans or greens if they fail.
Spring: Start peas and cool greens as soon as soil is workable. Sow lettuce every 10 days until late May. Direct-sow carrots and beets in April and again in mid-May.
Summer: Begin bush beans and squash in late May or after last frost. Sow a second bean planting 2 weeks later. Plant tomatoes and peppers as transplants after danger of frost.
Fall: In late July to mid-August, sow spinach, kale, and fast-maturing radishes for fall harvest. Protect with row cover when temperatures drop.
Focus on short-maturity varieties and heavy use of season extension.
Spring: Start seeds indoors for transplants 4-6 weeks before last frost. Direct-sow peas and radishes early. Use cloches and low tunnels to warm the soil.
Summer: Stagger two sowings of bush beans and fast squash varieties, but generally accept smaller harvest windows.
Fall: Prioritize cold-hardy brassicas and overwintered garlic. Use insulated cold frames for kale and lettuce.
You can fit more successions here.
Spring: Sow continuous plantings of salad greens and radishes.
Summer: Direct-sow multiple successions of cucurbits and beans; irrigate carefully to avoid bolting.
Fall: Later first frost allows another round of warm-season crops in some locations; still plan to protect from early freezes.
Seed depth and spacing: follow pack instructions, then thin to recommended spacing to avoid crowding in successive sowings.
Compost and fertility: replenish beds between successions. A light application of balanced organic fertilizer or compost tea when you remove a crop supports the new planting.
Mulch: reduces moisture loss under Colorado’s dry conditions and moderates soil temperatures. Use straw or shredded leaves carefully to avoid harboring slugs.
Watering: young succession seedlings need consistent moisture. Drip irrigation with timers is ideal to prevent stress and uneven germination.
Pest and disease rotation: avoid planting the same family repeatedly in the same bed. Rotate brassicas, legumes, and solanums across beds.
Intercropping quick and slow crops is a high-yield strategy.
Radish between carrots: radishes are harvested early, marking the row and loosening soil for carrots.
Lettuce under tomatoes: lettuce matures before tomatoes fully shade them.
Peas with fall brassicas: peas fix nitrogen early, benefiting later brassica plantings.
These pairings work well for Colorado gardeners who need to maximize limited space and season length.
Row covers: add 5-15 degrees F protection and speed early growth.
Low tunnels and cold frames: extend season by weeks to months.
Wall-o-water or cloches: protect transplants against cold snaps and allow earlier planting.
Shade cloth: protects cool-season crops sown for summer production from midday heat.
Using these tools lets you move sowing dates earlier and later, increasing the number of possible successions.
Succession planting is dynamic. Keep a garden log with dates sown, variety, germination rate, and harvest windows. Note frost events, heat spikes, and pest outbreaks. Use this record to refine intervals, variety choices, and protective measures for future seasons.
Overcrowding: thin seedlings early to prevent competition and disease.
Soil depletion: replenish organic matter and nutrients between crops.
Ignoring microclimates: plants in a sheltered corner can be planted earlier than exposed beds.
Poor timing: planting heat-loving crops too early leads to slow growth and susceptibility to cold injury.
Avoid these by planning, using season-extension, and having backup plantings of fast-maturing crops.
Know your local average last and first frost dates.
Select varieties with appropriate days-to-maturity for your elevation.
Stagger sowings: 7-14 days for greens, 2-3 weeks for roots and beans.
Use relay planting and intercropping to keep beds productive.
Amend soil and maintain regular irrigation between successions.
Use row covers, tunnels, or cold frames to extend early and late season plantings.
Keep records and adjust timing year-to-year.
Succession planting in Colorado is about timing, variety selection, and using your microclimate and tools to stretch a sometimes-harsh season into continuous production. With planned intervals, strategic relay plantings, and modest season extension, Colorado gardeners can harvest more evenly throughout spring, summer, and fall. Start small, record what works in your specific location, and gradually expand the system to fit your goals and space.