Growing Veggies in Northern Colorado

Growing Veggies in Northern Colorado Alison O Connor, PhD astoven@larimer.org CSU Extension in Larimer County csuhort.blogspot.com Vegetable Gardening Challenges Short season Hot days, cool nights Dry Poor(?) soil Windy Salty water Hail Grasshoppers Key to Successful Gardening is the Soil Organic matter living organisms, fresh residues and decomposed residues is an essential ingredient in fertile and healthy soils Organic Matter: Compost Apply 1 to 2 pounds per square foot in gardens for soil development Apply 0.5 to 1 pound per square foot applied for soil fertility maintenance. Most compost contains 1 to 3 percent nitrogen The target level for organic matter in healthy soil is 3 to 5 percent If you ve been gardening for awhile, consider getting a soil test! Weed Management Options for the Vegetable Garden Competition Mulches Mechanical methods Herbicides (traditional and organic ) Biological controls Container gardening Ability of Vegetable Species to Suppress Weeds Good Squash Beans Pumpkins Cucumbers Sweet corn Melons Irish potatoes Sweet potatoes Tomatoes Broccoli and Cabbage Poor Lettuce Carrot Pepper Greens Onions Peas Radishes 1

Mulch for Weed Prevention Makes it difficult for weed seeds to germinate or seedling weeds to survive Reduces evaporation from soil surface, cutting water use by 25 to 50 percent Organic mulches improve soil tilth and help lessen soil compaction Stabilizes soil moisture Prevents soil compaction Moderates soil temperature extremes Controls erosion Gives a finished look, improving aesthetic quality Grass Clippings as Mulch Grass clippings make good mulch when applied in thin layers and allowed to dry between applications Add additional layers each week the lawn is mowed With a few layers, weed seed germination will be checked Grass clippings decompose rapidly, requiring additional layers during the growing season A grass clipping mulch recycles its nutrients into the garden bed Do not use grass clippings from lawns that have been treated with herbicides or other pesticides, for at least four weeks after application Plastic Mulch Colored plastic will kill weeds more effectively than clear May enhance plant growth Will warm soil Can conserve water Can cause excessive soil wetness May encourage slugs and some insect pests May provide cover for rodents Irrigation/Watering Drip irrigation: increases efficiency reduces disease is easy to automate is easy to install and repair Can be used for beds and containers Disease Management Disease-free transplants Carefully inspect transplants for any spots or lesions on the stems or leaves Remove a few transplants from the planting container and inspect their root systems healthy roots are white or light in color, and show no signs of decay or excessive wrapping of the fibrous roots around the root ball Avoid buying plants that have already set fruit Disease Management Site selection Always choose a well-drained soil for growing vegetables Root rots and other soil-borne diseases thrive in wet soils Avoid planting close to trees or buildings that may reduce air circulation or the intensity or duration of sunlight Use raised beds to promote soil aeration and drainage 2

Disease Management Crop rotation Continuous cropping of plants in the same botanical family allows for buildup of disease organisms Vegetables that are in the same botanical family should not be grown in the same area for at least three years For example, rotating curcurbits with vegetables in the Solanaceae family can potentially lower the incidence of diseases Disease Management Plant spacing and training Dense plantings can often increase susceptibility to diseases By increasing the spacing between plants, air circulation and light intensity are enhanced, creating a less favorable environment for disease development Always stake or cage tomato plants to keep the plants and fruit from touching the soil Disease Management Sanitation Plant residues in a garden should be cleaned and removed Do not compost diseased plants Eliminate weeds around the perimeter of the garden because these can serve as hosts for plant diseases Why Garden in Containers? Allows gardening in small spaces Can be easier than conventional gardening for those with physical limitations Less daunting for beginners Weed-free gardening Can locate plants where they will grow best (sun/shade, out of wind) Can locate containers where it is more convenient for care and harvesting Can extend the growing season (earlier start in spring; can move/protect in the fall) Easier to protect plants from wildlife (rabbits, deer) Pots and Containers Just about anything that will hold growing media can work for container gardening Drainage is ESSENTIAL!!! Larger containers require more media Unglazed clay pots dry out quickly Larger plants (tomatoes) will need larger pots Root crops (carrots) will need deeper containers; lettuce, radishes, beans, and peas can be grown in shallower containers Container Size for Vegetables Container Size How Many Plants? Beets 2 gallon Thinned to 2-3 inches apart Cabbage 1 gallon 1 plant Carrots 2 gallon Thinned to 2-3 inches apart Cucumber 1 gallon 2 plants (use cages) Eggplant 2 gallon 1 plant Green beans 1 gallon 2-3 plants Leaf lettuce 1 gallon 4-6 plants Parsley 1 gallon 1 plant Pepper 2 gallon 2 plants Radishes 2 gallon Thinned to 1-2 inches apart Spinach 1 gallon Thinned to 3 inches apart Swiss chard 1 gallon 1 plant Tomatoes Cherry 1 gallon 1 plant (use cages) Standard 3 gallon 1 plant (use cages) 3

What to look for on a seed packet When Do I Start Planting Seeds? Outside of Package Crop Variety Scientific name Amount of seed in packet Days to Maturity General planting window Days to emergence Seed Depth Height (flowers) Seed Spacing Row Spacing Thinning Plant description Outside and Inside Starting Instructions (may vary for other seed companies) Sun requirements (flowers) Bloom Time (flowers) Seed Starting Rule #1: Don t Plant too Early! WHEN is governed by the last frost date for the area (for the summer garden) OR ambient soil temperature (for the spring garden) Consult your seed packets and catalogs for planting out dates and count backwards Planting the Spring Garden Planting based on soil temp for seed germination Soil temp 40-60 degrees Ambient air temp Can thrive in less sun Leafy crops tend to be sweeter with cooler weather Require crop protection when temps drop Planting the Summer Garden Requires warmer soil (>65 degrees) and warm ambient air temps Minimum of 6 hours of full sun Seeds can be started indoors or outside based on seed packet recommendations Timing based on the variety and the specifications on the seed packet Seed Trays Find what works for you Must have drainage holes! Seed trays should never sit in standing water Can purchase covers or use other materials Peat Pellets Good for finicky transplanters, such as squash, cucumbers, corn Expensive Take up more space 4

Reuse and Recycle Drainage essential Containers must be clean and sterilized Soapy water, 10% bleach solution Plastic is best Air dry Citrox Greenshield Heating Mat An expensive investment, but worth the expense if you re a serious gardener Buy a thermostat, or you will potentially cook your seedlings Keep at 70-75 degrees F Range in price (depending on size): $20-100 Thermostat: ~$20 Germination Medium Never use garden soil or potting soil Garden soil carries insects and diseases and is too dense for tiny seedlings to push their way through Potting soil generally too dense as well Too much water retention Purchase a seed starting medium Fine texture Lightweight Drains well May be difficult to moisten May contain peat moss, coir, perlite, vermiculite or fertilizer Planting the Seeds Fill cells with moistened medium Gently tamp do not pack down Gently sprinkle/place seeds on top Gently sprinkle with ¼ medium or vermiculite Gently tap the tray to ensure seed to soil contact Spritz with water Label with the plant name and date Keep the seed packet in your records Moisture Spritz lightly after planting Dome or plastic to create a terrarium effect Monitor soil moisture as the seeds sprout The End of Germination Germination ends when the first set of true leaves emerge and the cotyledon falls off 5

Procedure to Maintain Seedlings Continue warmth and even moisture Watering Fertilization Air circulation Light Light requirements Fluorescent lights are inexpensive and work as well as grow lights Two cool white fluorescent bulbs Keep them 2-4 above the seedlings (so the plants don t stretch) Install a timer so the lights are only on for 12-16 hours a day The seedlings need darkness to develop properly Watering Your biggest challenge More water does not make seeds grow or germinate any faster Mist Water from below for uniform watering and to keep seeds in place Fertilization Begin fertilizing when true leaves emerge Apply via irrigation (fertigation) Use any complete fertilizer (example: 10-10- 10) follow the label on the fertilizer label for mixing instructions Do not mix in a stronger concentration! When plants are young, consider a ¼ rate and increase as plants grow larger Strengthening Seedlings Use a fan in the area to increase air flow to prevent disease problems and increase seedling strength Air flow mitigates potential moisture problems Touch Review: Success Tips for Seed Starting Use clean dry seed that are good varietal choices for your location Chart planting, journal results Use clean, sterile, well drained containers Use sterile soilless medium Provide adequate moisture, light, warmth Provide good circulation 6

Planning your Schedule General inside start seedling growth guideline (germination time is NOT included in this time) 2 to 4 weeks: cucumber, melons, squash, lettuce 5 to 7 weeks: broccoli, Brussels sprouts, cabbage, cauliflower, tomatoes 6 to 9 weeks: eggplant, leeks, onions, peppers, some herbs Planting Your Transplants Outside Don t wait too long Hardening off Prepare planting area before bringing the transplants out (especially if it s a hot day) Water well Sowing Seeds Outdoors Large seeds are generally better at sowing directly outside Roots crops should be directly sown Prepare your garden with fine soil enriched with compost Remove any large stones or weeds Leaf lettuce Spinach Kale Beets Swiss chard Beans VEGETABLES Peas Carrots Radishes Turnips Zucchini FLOWERS Marigolds Cleome Impatiens Foxglove Sweet peas Cosmos Forget-me-nots Sowing Seeds Outdoors Space and plant to depth according to recommendation If seeds need light to germinate, do not cover with soil Make sure the seeds have good contact with the soil by tamping it down gently after sowing Water the soil gently to avoid disturbing the seeds and do not allow it to dry out Thin the seedlings according to package after germination and development of first true leaves Peas Peas can be planted very early in the spring 4-6 weeks before the last frost soil temperatures can be as low as 40 degrees up to 80 degrees F Space seeds 4-6 apart They like to germinate warm and grow cool, so you can pre-sprout them inside and will take between 6 and 15 days to germinate Use a damp paper towel and a plastic bag to presprout, then move sprouts out to the already prepared garden bed Typically will take 65 days to harvest Brassicas Seeds can germinate in soil temperatures as low as 40 degrees F Cole crops germinate better in warmer soil, they typically are best started from transplants in the spring; days to harvest are from transplants Transplant when the first true leaves have emerged Chinese Kale, broccoli and cauliflower can be started indoors 6 to 8 weeks before last frost plant in moist media plant seeds ½ deep Be sure to harden seedlings off before transplanting 7

Lettuce Bibb, Romaine, Loose Leaf, etc. Start the first round inside as transplants 2-3 weeks prior to planting Direct sow successive rounds outside once soil warms For early spring plantings, use varieties that mature in ~50 days Choose heat tolerant varieties for hot summer months Head types will do better planted mid summer (after summer solstice) Use a shallow planting depth of ¼ to ½ inch, thin to 4 8 inches Seed to baby greens in 5 6 weeks, Seed to salad size in 6 8 weeks Beets, Carrots, Radishes, Swiss Chard These can be planted from seed outdoors 2 to 4 weeks before the last frost date Soil temps can range from 35⁰ F for parsnips to 80⁰ F for optimal germination which should take between 7 to 14 days If you desire more reliable germination, soak in a damp paper towel 24 hours before planting Beets and carrots WILL require thinning Total days to harvest will vary depending on crop but can start as soon as 60 days from planting Solanaceous Crops Start seeds prior to last frost date: Tomato: 6 8 weeks Peppers: 8 10 weeks Eggplant: 7 10 weeks Plant seeds indoors at a depth of 1/4 Temperature of media is ideal at 80 F for germination Harden-off tender transplants prior to planting outside Consider delaying transplanting until 1-2 weeks after frost date Plant tomato transplants deep as roots will form on stems Cucumbers, Squash, Melons etc. Vine crop (cucumbers, squash, melons) roots are extremely intolerant of being disturbed, and perform best when grown by direct seeding or using transplants that are small, young plants, not more than 2-3 weeks from seeding For transplants: start seeds 3-4 weeks prior to last frost date Plant outside when soil temperature is >65 degrees F Plant seeds at a depth of 1 inch Harden-off tender transplants prior to planting outside Beans Bush and Pole Varieties Direct sow outdoors (late May to early June) Green beans don t germinate well in soils below 60 F Plant to a depth of 1 to 1 ½ inch deep Plant at least 6 inches apart, use wider spacing if growing beans for drying Light fertilizer needs, too much N will encourage more leaves and delay fruiting Regular water required for straight beans Sweet or Indian Corn Direct sow corn seeds after the danger of frost is over Soil germination temperature is ideal at 50 60⁰ F Plant two corn seeds in each hole, spacing the holes about 12-15 inches apart Plant in rows 30-36 inches apart, planting several rows together forming a block of rows Thin the corn to one plant from each hole 8

Container Carrots Plant in 1 quart container or larger 2 to 3 inches between plants Full sun to part shade Succession sow Ruby Queen Nelson Short n Sweet Thumbelina (AAS) Container Cucumbers Use 1 gallon or larger pot Space 14 inches between plants Full sun, warm season crop Trellis vines or plant bush types Salad Bush Hybrid Spacemaster Bush Pickle Burpless Liberty Dragon s Egg Container Green Beans Pole beans give bigger yield in small space Use 2 gallon pot or larger Space 2 to 3 inches between plants Full sun Succession sow bush types over several weeks Blue Lake Kentucky Wonder French Dwarf Topcrop Plant Early Grow for shoots or pods Container Peas Little Marvel- bush type, heavy yields Tom Thumb super dwarf, ideal for containers Container Sweet Peppers Container Chile Peppers Almost any pepper is suited to containers Peppers like it hot! Place in full sun One plant per 2-gallon container Tequila Lipstick Sweet Banana Gypsy Yolo Wonder Pizza My Heart Cherry Belle Jalapeno Cajun Belle (AAS) Red Cherry Cherry Bomb Apache Chile Long Red Cayenne Holy Mole (AAS) Cajun Belle 9

Container Summer Squash Bush type is best Plant one plant per 5-gallon pot Full sun Ronde de Nice Gold Rush Gold Neck Dixie Early Prolific Straightneck Winter Squash 1 plant per 5 gallon container Full sun Bush types best - Honey Bear (AAS) - Bush Delicata (AAS) - Butterscotch (AAS) Swiss Chard Plant in one-half- gallon or larger pot 4 to 6 inches between plants Full sun to part shade Pluck leaves, not entire plant Pot of Gold Bright Lights Peppermint Cherry Tomatoes Vines can be huge, go with dwarf types 1 plant per 1-gallon pot, full sun Trellis Fantastico (AAS) Patio Pixie Tiny Tim Saladette Sweet 100 Patio Spring Giant Tumbling Tom Small Fry Lizzano (AAS) Sungold larger container; needs support Heirlooms: Zebra, Black and Currant Tomatoes Larger Tomatoes Use dwarf types so plant stays small Cage or trellis Prune off side suckers 1 plant per 5-gallon container Full sun Super Bush Demidov Husky family Herbs for Containers Most herbs will grow well in containers Can keep them going well past fall by moving them inside/outside Good performers: Parsley Sage Basil Thyme Rosemary Mints Chives Dill 10