Zone 6 Planting Guide: Your Month-by-Month Calendar for a Thriving Garden

January

January in Zone 6 is all about winter garden maintenance and preparing for the vibrant growing season ahead. While the landscape may be blanketed in snow, there’s plenty you can do to ensure a successful and bountiful garden in the coming months. Focus on protecting your existing plants from the harsh winter conditions and laying the groundwork for spring planting.

Protect Trees and Shrubs: Ice and heavy snow can cause significant damage to tree and shrub limbs. Regularly check your trees and gently brush off any accumulated snow or ice to prevent breakage. For newly planted trees and species with delicate bark, such as linden, ash, mountain ash, and maple, apply tree wrap to their trunks to guard against sunscald and frost cracks.
Indoor Houseplant Care: Winter can be tough on indoor plants too. Dust buildup on leaves hinders their ability to photosynthesize. Give your houseplants a refreshing clean by wiping down their leaves with a soft, damp cloth soaked in water with a touch of mild, scent-free soap. This will improve light penetration and gas exchange, keeping them healthy and vibrant.
Garden Planning and Design: January is the perfect time to immerse yourself in garden catalogs and start planning your spring and summer gardens. Review your garden journal from the previous year to analyze crop rotation strategies and decide on the layout for the upcoming season. Consider starting carpentry projects like building cold frames or trellises, and setting up indoor grow lights if you plan to start seeds indoors.
Seed Stratification: Many perennial seeds require a period of cold stratification to break dormancy and germinate successfully. Begin this process in January by either sowing these seeds outdoors in protected areas or mimicking winter conditions by placing them in your refrigerator. This cold treatment is crucial for their spring germination.
Review and Refine Planting Records: Take time to analyze your planting, fertilizing, and pest control records from the previous year. Identify successful plant varieties and note any that underperformed. Use this information to create your seed and plant orders, ensuring you re-order favorites and explore new varieties.
Houseplant Pest Inspection: Winter indoor conditions can sometimes favor houseplant pests. Thoroughly inspect all houseplants for any signs of insect infestations. If you’ve received any holiday plants, quarantine them away from your other houseplants until you’re sure they are pest-free.
Start a Garden Journal: If you don’t already have one, resolve to keep a garden journal this year. Document your planting dates, varieties, successes, and failures. Note which flowers and vegetables thrived and which struggled in your Zone 6 garden. This journal will become an invaluable resource for future garden planning.
Order Seed Catalogs and Pre-order Plants: Request seed catalogs from various companies now to get inspiration and ideas for your garden. Explore companies specializing in open-pollinated and heirloom varieties for unique and resilient plants. Pre-order bulbs and live plants from your preferred suppliers to secure the varieties you want and avoid sell-outs when planting season arrives.

February

February in Zone 6 marks the transition from deep winter to the anticipation of spring. While it’s still cold, the days are getting longer, and the gardening season is just around the corner. Focus on continuing your preparations, starting some early seeds indoors, and taking advantage of any warmer days for outdoor tasks. Proactive steps now will set you up for a smoother and more productive spring.

March

March is when gardening activities in Zone 6 truly ramp up. It’s time to start seeds indoors for many vegetables and flowers, prepare your garden beds, and even get some early crops planted outdoors as the weather begins to moderate. Be prepared for fluctuating temperatures and keep an eye on the forecast, but embrace the start of the growing season!

Prune Fruit Trees and Berry Bushes: If you haven’t already, early March is an ideal time to prune your fruit trees, berry bushes, and other woody ornamentals. Prune while plants are dormant, before new spring growth begins. This promotes healthy growth and fruit production.
Plant Early Outdoor Crops: As soon as the soil can be worked, plant potatoes, strawberries, asparagus crowns, rhubarb, and onion starts. These crops are cold-hardy and can get a head start in the cooler spring weather.
Direct Sow Hardy Flower Seeds: Direct sow seeds of hardy annual flowers like Nigella, Poppy, and Delphinium outdoors. The cold temperatures of early spring will aid in their germination.
Repot and Fertilize Houseplants: With longer days and increased light, houseplants will start to resume active growth. Repot any that have outgrown their containers and give them a balanced fertilizer to encourage healthy new growth.
Start Warm-Season Seeds Indoors: Early in March, start seeds indoors for eggplant, peppers, and tomatoes. These vegetables require a long growing season and need to be started indoors to mature in Zone 6.
Service Garden Tools: Beat the spring rush by taking your lawn mower and other power tools in for servicing now. Ensure they are in good working order before the busy gardening season begins.
Turn Compost Pile: On warmer days, turn your compost pile to aerate it and speed up decomposition. Avoid working your garden soil when it’s still too wet, as this can lead to soil compaction.
Clean Up Garden Beds: Remove any leftover dried plant debris from garden beds and add it to your compost pile. Clearing out old debris helps prevent disease and pest issues in the new season.
Fertilize Berries: Fertilize grapes, raspberries, and blueberries with a fertilizer formulated for berries before new growth begins.
Maintain Garden Journal: Keep your garden notebook handy and record everything you plant. Include details like seed company, plant variety, planting date, and expected harvest date. Throughout the growing season, note plant performance, disease susceptibility, and treatments used. This detailed record-keeping is invaluable for future planning.
Install Birdhouses: Place birdhouses you built over the winter outdoors this month. Birds will soon be looking for nesting sites, and attracting them to your garden can help with natural pest control.
Soil Testing: Now is a good time to get your soil tested to determine its nutrient levels and pH. Contact your local Extension Agency for soil testing kits and instructions. Soil test results will guide your soil amendment and fertilization strategies.
Remove Winter Protection: Towards the end of March, gradually remove winter protection from perennials and pull back mulch from strawberry and asparagus beds to allow new growth to emerge easily. Side-dress asparagus with a gentle, natural nitrogen fertilizer.

April

April in Zone 6 is a month of transition and increasing activity in the garden. While warmer weather is tempting, be cautious of late frosts and focus on hardening off transplants and direct sowing cool-weather crops. It’s a busy month balancing indoor and outdoor gardening tasks.

Harden Off Transplants: Start hardening off cool-season transplants like onions, parsley, and early cole crops (broccoli, cauliflower, cabbage, Brussels sprouts) that are at least 5 weeks old. Introduce them gradually to outdoor conditions to prevent shock. Choose smaller cole crop transplants as overly mature plants exposed to early cold are more prone to bolting.
Monitor Rainfall: Place a rain gauge near your garden to track rainfall. Aim for about one inch of water per week from April to September, either through rainfall or irrigation.
Direct Sow Cool-Season Crops: Sow seeds directly outdoors for a wide range of cool-weather vegetables: asparagus, beets, carrots, Swiss chard, kohlrabi, leaf lettuce, mustard greens, parsnips, peas, radishes, spinach, and turnips.
Scatter Annual Flower Seeds: Sow annual flower seeds in flower borders. Fine seeds require no covering and will germinate quickly, providing early summer color.
Hill Potatoes: Continue “hilling up” potatoes as the sprouts emerge. This encourages more potato production and prevents greening.
Plan Landscaping Projects: Plan new landscaping projects on paper before planting. Consider mature plant sizes and spacing to avoid overcrowding.
Prune Raspberries: Prune raspberry canes that will produce this year’s crop back by about ¼ of their length. Remove last year’s fruiting canes if you haven’t already.
Harden Off Frost-Sensitive Plants: By mid-April, begin hardening off frost-tender transplants, including vegetables, herbs, and both perennial and annual flowers that you started indoors.

May

May is a pivotal month in Zone 6 gardening, typically marking the average last frost date. After this date, it’s generally safe to plant tender seedlings outdoors. However, always check local weather forecasts and recommendations, as last frost dates are just estimates. May is a time of intense planting and establishing your warm-season garden.

Start Warm-Season Seeds Indoors (Continued): You can still start seeds indoors for okra, squash, cucumber, melons, and watermelons. Sow vining crops in peat pots to minimize root disturbance during transplanting.
Succession Planting Cool-Season Crops: Sow another round of seeds outdoors for beets, carrots, Swiss chard, kohlrabi, late cabbage, leaf lettuce, mustard greens, collards, turnips, radish, spinach, bunching onions, and peas for a continuous harvest.
Plant Trees and Shrubs: Plant any new trees and shrubs by the end of May to allow them to establish roots before the heat of summer.
Hill Potatoes (Continued): Continue hilling up potatoes as needed.
Install Tomato Trellises: Set up trellis systems for your tomato plants before they start sprawling. Early support makes management easier.
Plant Warm-Season Crops Outdoors: If the weather is favorable after the last frost date, direct sow seeds outdoors for beans, okra, squash, sweet corn, and watermelon. Plant partial rows of beans and sweet corn for successive plantings every week or two to extend the harvest. Plant sweet corn in blocks for better pollination.
Move Houseplants Outdoors: By the end of May, it’s usually safe to move houseplants outdoors to a shady location for their summer “vacation.”
Plant Sweet Potato Slips: Plant sweet potato slips after the soil has warmed up sufficiently, which might be late May or early June.
Direct Sow Warm-Season Flowers and Herbs: Direct sow sunflower, nasturtium, marigold, borage, basil, and other warm-season flowers and herbs directly into garden beds.

June

June in Zone 6 is a month of rapid growth and abundant harvests. Focus on maintaining your garden through regular weeding, watering, and pest monitoring. Succession planting is key to extending your harvest season, and early pest control is crucial for a healthy garden.

Protect Brassicas from Pests: Cover Brassica crops (broccoli, cabbage, kale, etc.) with floating row covers to protect them from cabbage moths and flea beetles, especially if these pests have been problematic in previous years.
Monitor and Control Colorado Potato Beetles: Watch for Colorado potato beetle adults, eggs, and larvae. Hand-pick them or use organic insecticides. Identify them by their yellow-and-black stripes (adults), yellow eggs on leaf undersides, and humpbacked red larvae on stem tips.
Cucumber Beetle Control: Be vigilant for striped and spotted cucumber beetles, which can transmit bacterial wilt to squashes and melons. Hand-pick adults and eggs throughout the season.
Mexican Bean Beetle Watch: Monitor for Mexican bean beetles. Consider using floating row covers as seedlings emerge to protect beans.
Aphid Management: Aphids are common in warm weather. Look for them on new foliage and sticky leaves (honeydew). Spray leaves with a strong jet of water to dislodge them. Insecticidal soap can also be effective, requiring repeat applications.
Squash Vine Borer Prevention: Watch for squash vine borer moths. They lay eggs at the base of squash vines. Examine stems daily and remove eggs. Wrap the lower stems with foil or row cover to prevent egg-laying.
Softwood Cuttings: Early June is a good time to take softwood cuttings of shrubs like spirea, lilac, and viburnum to propagate new plants.
Watering Practices: Avoid working in the garden when leaves are wet to prevent disease spread. Water established vegetable gardens deeply once a week rather than shallowly daily to encourage deep root growth and drought tolerance.
Manage Spring Crop Harvest: Hot weather can cause lettuce to bolt and become bitter. Harvest spring crops as they mature and plant warm-season crops in their place.
Prevent Blossom End Rot: Prevent blossom end rot on tomatoes, peppers, squash, and watermelons by maintaining consistent soil moisture, mulching, and planting in well-drained soil. Avoid deep cultivation near plants. Bone meal can help correct calcium deficiencies contributing to blossom end rot. Avoid high-nitrogen fertilizers.
Succession Planting Warm-Season Crops: Continue seeding warm-season vegetables like beans, summer squash, and cucumbers for a continuous supply.
Regular Weeding: Weed the garden regularly to keep weeds manageable and prevent them from competing with your crops for nutrients and water.

July

July in Zone 6 is peak harvest season! Stay on top of harvesting vegetables as they ripen to encourage continued production. Regular deadheading of flowers and succession planting for fall crops are also important tasks this month.

Start Fall Cole Crop Seeds: Start seeds indoors now for heading cole crops like broccoli, cabbage, and cauliflower for your fall garden. Direct sow radishes, carrots, beets, turnips, and kale in late July and August for fall harvests.
Tomato Leaf Spot Monitoring: Watch tomato plants for signs of leaf spot diseases and take action if needed.
Pest Monitoring (Continued): Continue monitoring for pests listed in the June task list and implement control measures as needed.
Deadheading Flowers: Deadhead spent flowers on annuals and perennials to encourage more blooms and redirect plant energy to flower and root production.
Fertilize Annual Flowers: Fertilize flowering annual plants with a balanced fertilizer once flowering begins and again before the end of the season to support continuous blooming.
Succession Planting for Late Crops: Sow seeds throughout July for late crops of beets, bush beans, carrots, Swiss chard, cucumbers, and summer squash. Cover seeds with pre-moistened potting mix to prevent crusting and use a thin layer of mulch or row cover to retain moisture.
Divide Bearded Iris: Divide and transplant bearded iris after they finish blooming using the vigorous ends of the rhizomes. Discard the old center portion and cut leaves back to about six inches.
Mosquito Control: Control mosquitoes by eliminating stagnant water sources. Consider installing a bat house to encourage bat habitats, as bats are natural mosquito predators.
Watering Practices (Continued): Ensure your garden receives about one inch of water weekly, ideally through early morning watering. Mulch plants to conserve moisture and improve yields.
Container Plant Care: Check soil moisture in container-grown vegetables and flowers daily, as they may need watering twice a day in hot weather.
Pinch Herbs: Pinch flowers off herbs like basil, mint, and oregano to promote bushy growth and leaf production.
Harvest Onions and Garlic: Harvest onions and garlic as the tops dry and fall over. Braid garlic tops and hang them in a cool, dry place. Cut onion tops back to one inch and dry bulbs thoroughly before storing. Use any damaged produce immediately.

August

August in Zone 6 is still a busy gardening month, though the intensity starts to ease slightly. Continue with weeding, watering, pest control, and harvesting. Begin clearing out spent crops to make way for fall plantings and prepare for the transition to cooler weather.

Sow Fall Peas: Sow peas in mid-to-late August for a fall crop.
Pest and Disease Management (Continued): Continue regular pest and disease inspections and take action as needed.
Raspberry Pruning: After the last raspberry harvest, prune out old fruiting canes, leaving only 3-4 young canes per foot of row for next year’s production. Wait until spring to prune back shoot tips.
Avoid Late-Season Pruning: Avoid pruning trees and shrubs now, as late-season pruning can stimulate new growth that won’t harden off before winter. Delay pruning until late winter or early spring.
Order Spring Bulbs: August is a good time to order and plant spring-flowering bulbs for next year’s early spring display. Plan for a succession of bloom times to extend the flowering season.
Sow Late Season Greens: Sow seeds for a late crop of leaf lettuce, mustard greens, Swiss chard, and spinach.
Deadheading Flowers (Continued): Continue deadheading flowers to encourage a final flush of blooms before the end of the season.
Mark Dormant Perennials: Some perennials and bulbs will start to go dormant this month. Mark their locations with popsicle sticks or create a garden map so you don’t disturb them during fall cleanup or spring planting.
Container Plant Watering: Check moisture levels in hanging baskets and containers daily as they may dry out quickly in late summer heat.
Harvest Summer Squash and Zucchini: Pick summer squash and zucchini frequently (every day or two) to encourage continuous production.
Remove Spent Plants: Remove old plants that have stopped producing to eliminate potential shelters for insects and disease organisms.
Weed Control (Continued): Control weeds before they go to seed to reduce weed pressure next year.
Sow Biennial Flower Seeds: Sow seeds of biennials like hollyhock and foxglove for blooms the following year.
Divide Daylilies: Dig, divide, and move daylilies after they have finished blooming.
Harvest Cantaloupe: Harvest cantaloupe when the stem easily separates from the fruit with gentle pressure.
Sow Cover Crops: If using a fall cover crop, sow seeds in late August to improve soil health over the winter.

September

September in Zone 6 is a month of transition as the garden shifts from summer abundance to fall harvest and preparation for winter. Focus on harvesting storage crops, planting fall vegetables, and preparing your garden beds for the dormant season.

Plant Fall Greens and Radishes: Leaf lettuce, Swiss chard, spinach, and radishes can still be planted for fall harvests.
Pest Monitoring (Continued): Continue inspecting for pests, especially bean beetles, which can have a second wave in the fall.
Bring Houseplants Indoors: Bring houseplants that have been outdoors for the summer back inside before temperatures drop too low. Hose them down to remove insects before bringing them indoors and quarantine them for a couple of weeks to monitor for any emerging pests.
Prepare Mulch for Winter: Make preparations for mulching your beds for winter protection. Bagged mulch is readily available, or consider getting a truckload delivered for larger gardens.
Divide and Transplant Spring-Flowering Perennials: Fall is an excellent time to divide and transplant spring-flowering perennials. Cut back tops and replant in well-prepared beds with added organic matter.
Harvest Pumpkins and Winter Squash: Harvest pumpkins, summer squashes, and gourds intended for storage before the first frost. Handle pumpkins carefully to avoid bruising, which can shorten storage life.
Harvest Fall Vegetables: Continue harvesting cool-season vegetables like radishes, lettuce, cabbage, Swiss chard, spinach, broccoli, and other cole crops. Some vegetables, such as parsnips, Brussels sprouts, and kale, actually improve in flavor after a frost.
Avoid Late-Season Fertilizing: Allow plants to naturally slow down and prepare for dormancy. Avoid late-season fertilization or heavy pruning, which can encourage new growth that will be vulnerable to frost damage.
Improve Garden Soil: Fall is an ideal time to improve your garden soil. Add manure, compost, and leaves to increase organic matter content. Wood ashes can be used as a top dressing to add phosphorus, potassium, and calcium.
Weed Strawberry Beds: Keep strawberry beds weed-free in the fall to reduce weed pressure next spring.
Plant Cover Crops: Get fall cover crops planted by mid-September to improve soil health over the winter and prevent erosion.

October

October in Zone 6 is the final major planting month of the season. Focus on planting garlic, shallots, and spring-flowering bulbs. Harvest any remaining tender crops before frost and begin storing your harvested produce. Seed saving is another important task for October.

Plant Garlic, Shallots, and Onions: Plant garlic, shallots, walking onions, and potato onions this month. These crops need fall planting to overwinter and produce next season.
Plant Spring Flowering Bulbs: Plant spring-flowering bulbs like tulips, daffodils, and hyacinths for a beautiful spring display.
Winterize Watering Systems: Drain hoses and empty bird baths before hard frosts to prevent damage.
Protect Potted Perennials: Bury potted perennials in an empty garden bed or surround them with straw for winter protection.
Collect Soil Samples for Testing: Collect soil samples for testing now to prepare for next year’s fertilization plans. Submit separate samples for different garden areas.
Divide and Transplant Perennials: Divide and transplant spring and summer-flowering perennials now. Wait until spring to divide fall-flowering perennials. Cut back foliage, replant, and water well. Mulch later in the winter.
Harvest Remaining Tender Crops: Keep an eye on the weather forecast and harvest any remaining summer produce like beans, eggplant, peppers, and tomatoes before hard frost.
Harvest and Preserve Herbs: Cut and dry or freeze any remaining herbs for use throughout the winter.
Asparagus Bed Cleanup: Remove and compost asparagus tops after they have yellowed and died back. Wait until the ground freezes to mulch asparagus beds.
Save Seeds: Save seeds from your favorite self-pollinating, non-hybrid flowers like marigolds. Dry seeds thoroughly and store them in a cool, dry, dark place.
Garden Variety Review: Review your garden notes and make note of productive and unsatisfactory vegetable varieties to inform your plans for next year’s garden.
Leave Seed Heads for Birds: Leave seed heads on asters, sunflowers, and cosmos for birds to feed on during the winter months.

November

November in Zone 6 is about extending the season as much as possible and completing final garden cleanup tasks. Explore season extension techniques for cold-tolerant greens and prepare your garden for the full onset of winter.

Extend the Season for Cold-Tolerant Greens: Experiment with season extension techniques like mini hoop houses, cold frames, or repurposed milk jugs to protect cold-tolerant greens like kale, spinach, and lettuce and extend your harvest.
Plant Remaining Spring Bulbs: If you haven’t already, plant any remaining spring-flowering bulbs now.
Clean and Store Planters: Empty, clean, and store planters in a dry place for the winter.
Winterize Rain Barrels: Empty and turn over rain barrels to prevent freezing damage and disconnect downspouts to direct water away from your foundation during winter.
Harvest Cole Crops: Cole crops like Brussels sprouts, cabbage, broccoli, collards, and kale become sweeter after frost. Continue harvesting them as long as possible. Low tunnels can further extend their harvest season.
Protect Late-Season Crops in Garden: Instead of harvesting less hardy late-season crops like carrots, beets, leeks, rutabagas, turnips, winter radishes, Swiss chard, Chinese cabbage, and leaf lettuce, leave them in the garden and mulch them heavily with straw for protection from freezing. Use floating row cover under straw for leaf lettuce to keep it clean.
Amend Garden Soil with Organic Matter: Spread manure, sawdust, straw, and shredded leaves over the garden and till them in to improve soil fertility, structure, and water-holding capacity.
Houseplant Pest Check (Continued): Continue checking houseplants for any pests brought indoors.
Apply Winter Mulch: Once the soil is frozen to at least an inch thick, apply a 2-4 inch layer of protective mulch to garden beds.
Service Power Equipment: Oil and store gas-powered equipment like lawn mowers and leaf blowers. Schedule tune-ups and blade sharpening during the off-season.
Order Seed Catalogs for Next Year: Order seed catalogs now for winter garden planning in January. Explore companies specializing in open-pollinated and heirloom varieties.

December

December in Zone 6 is a time for reflection and planning. As the gardening year concludes, evaluate successes and failures, consider new experiments for next season, and enjoy the winter rest before the cycle begins again.

Consider Garden-Related Gifts: Give memberships to local botanical gardens, arboretums, or nature centers as holiday gifts.
Protect Young Trees from Winter Damage: Protect trunks of young trees with tree wrap and surround multi-stemmed shrubs with chicken wire or hardware cloth to protect them from rabbits and rodents.
Clean and Sharpen Garden Tools: Clean garden tools with a wire brush and apply oil to prevent rust. Sharpen hoes and spades and clean and sharpen pruning tools. Sand handles and apply linseed oil or paint them a bright color for visibility.
Drain Fuel from Power Equipment: Drain fuel tanks of lawn mowers and tillers before storing them for the winter.
Apply Mulch (Continued): If not already done, apply a thick layer of mulch to all planting beds, especially around perennials.
Mulch Root Crops for Winter Harvest: A thick layer of straw over root crops like parsnips, carrots, leeks, and beets will protect them for harvest well into winter.
Use Plant-Safe De-icing Products: Avoid rock salt (sodium chloride) for de-icing, which can damage plants. Use calcium chloride or potassium chloride products instead. For traction, use sand, kitty litter, or wood ashes sparingly.
Review and Expand Garden Notes: Review and expand your garden notes to help with planning and improvements for next year’s garden.

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