“Last year my tomatoes struggled a lot. I think my soil might be tired. Should I rotate spots or should I fortify the soil? Thank you.” Question from Lucinda of Pittston, Maine
Answer: Tomatoes must be rotated on a three-year cycle for best performance, especially if they have experienced diseases. They are heavy feeders, experience lots of soil-borne diseases that can carry over in the soil from year to year, and root-knot nematodes are common pests that lower production and can live in the soil from year to year. Rotation fixes all of these problems. I recommend rotating tomatoes with soil-fortifying crops, such as peas and beans, which naturally add nitrogen to the soil. Tomatoes take up lots of nitrogen and fertilizer!
From there, I also suggest that you try short-season varieties adapted to northern climates. You can find several listed in the first article below.
“How early can potatoes be planted in zone 5?” Question from Lisa of Berwick, Maine
Answer: Your last frost date is May 10th, and you have a growing season that is approximately 142 days long, according to the Old Farmer’s Almanac. You can plant potatoes in the ground as early as four to five weeks before your last frost date, so that would be early April in Berwick, Maine. You can also plant them a bit later. Potatoes grow well in your cool summers. Keep in mind that there are early, mid-season, and late-season potatoes that take varying amounts of time to be ready for harvest, so consider this when choosing the best potato varieties for your garden. Generally, earlier types are better for northern climates. (Johnny’s Selected Seeds is a great potato source for your region.)
Potatoes should be planted 6 to 12 inches apart in rows around 2 to 3 feet apart. They like deep, friable soil, so consider planting them in mounds amended with quality compost, such as Black Gold Garden Compost Blend, which is OMRI Listed for organic gardening. Cover each seed potato with at least 3 inches of soil. In your cold region, planting them a bit deeper might be wise.
“What would be a good fruit to try and grow in a cold climate?” Question from Chelsea of Alpena, Michigan
Answer: Lots of classic garden berries are very hardy and grow beautifully up north. Blackberries, blueberries, currants, gooseberries, strawberries, and raspberries are among them. If you are new to berry planting, I would start with lowbush blueberries because they are quick to set fruit, easy to maintain, and very hardy.
Blueberries (Vaccinium spp.) grow particularly well up north and are able to withstand climates far into Canada. Choose compact lowbush varieties that are easy to maintain. Two classics that are short, heavy-bearing, and flavorful are ‘Northblue‘ and ‘Northcountry‘. These would look right at home along the edge of a sunny patio or even in containers. Speaking of container berries, the new designer lowbush blueberries in the Bushel and Berry® Series are also excellent varieties to try. (In fact, all of there berries are quite hardy and low-care). Of these, I think Blueberry Glaze® is especially beautiful because of its tidy, boxwood-like habit and tasty berries.
Alpena, Michigan is blueberry country, so you should not have trouble growing them, but you should still know the basics. Plant your berries in full to partial sun. The key to happy blueberries is getting their soil right; they like well-drained, acid soils with a pH between 4.5 and 5.5. When soils are too alkaline (have a higher pH) blueberry plants cannot access necessary nutrients, and their leaves start to turn yellow. To keep this from happening, amend the soil with Canadian Sphagnum Peat Moss at planting time and feed with a fertilizer formulated for acid-loving crops, like blueberries. Water your berries if rain has been infrequent and the soil starts to become dry. If you start with robust, good-sized plants this spring you will have berries by summer.
If you are interested in growing other berries on a small-scale, read our article about the best fruits for container gardening. If you are interested in growing strawberries, watch the video below.
“I live in zone 5B and was wondering if I can grow artichokes. If so, how would I go about doing that so that I can have edible flower buds? Thanks!” Question from Trish of Newton, New Jersey
Answer: It’s all about timing, choosing the right artichoke variety, and giving the plants good care.
Timing: Start your plants indoors from seed early–in February or March. Artichokes are very easy to start from seed, but they need lots of sun and have a tap root, so start them in a deeper pot–something no smaller than a 4-inch pot. Expect them to grow quickly.
Choosing the right variety: The only artichokes that northerners can successfully grow are those that bloom in the first year. Three good choices are ‘Colorado Star‘, ‘Tavor‘, and ‘Imperial Star‘.
Giving them good care: Full sun in a necessity. Plant your artichokes in a garden bed with quality soil that drains well. Amending your garden soil with Black Gold Garden Soil at planting time is recommended. Be sure not to overwater your plants; they like it on the dry side once they are established.
For all the details in between, please watch the Black Gold video about growing artichokes un North below.
“How late can one start seeds inside for planting a garden in Zones 3-4?” Question from Jill of Greybull, Wyoming
Answer: It depends on what you are planting. Some crops are fast-growing, yielding vegetables or flowers in a matter of weeks (please see the video below). Others take more time and need the warmth of summer to grow to full potential. For indoor seed-starting we recommend planting in natural & organic Black Gold Seedling Mix.
Start warm-season vegetables no later than early March. When you have a short growing season, it is important to jump-start the season by getting warm-season, summer vegetables planted and growing inside early. The bigger your tomatoes, peppers, beans, and even pumpkins and melons at planting time, the better. Get them planted outside as soon as possible, after your last frost date.
Start cool-season vegetables any time from spring to late summer. Cool-season vegetables, like greens, cabbage, carrots, and peas, can be planted from spring through fall.
Here are some more Q&A blogs for northern gardeners that you may consider reading.
“Is it possible to grow fruit trees at 10,000 ft. in elevation (Rocky Mountains)” Question from Wolf of Westcliffe, Colorado
Answer: Fruit trees able to produce at high altitudes must be able to tolerate cooler, shorter growing seasons and cold winters. There are several very early fruit-bearing trees able to tough it out. Ideally, trees should also be late to flower, for spring pollination and fruit set. The University of Minnesota breeds many fruits, particularly apples, that survive under these conditions (click here to learn more). Here are a handful for you to consider.
Fruit Trees for High Elevations
Apple ‘Centennial Crabapple’ (Zone 3): a tasty crabapple good for eating fresh or making sauce that ripens in late August.
Apple ‘State Fair’ (Zone 4): a tart, sweet eating apple that ripens in August.
Apple ‘Lodi’ (Zone 3): cooking apple for pies and sauce that bears in August.
Pear ‘Summercrisp’ (Zone 4): crisp, sweet pears are produced in August.
When buying a hardy fruit tree, ask about rootstock. Some rootstocks impart more hardiness than others.
Rocky Mountain Native Fruits for High Elevations
Sometimes it pays to go native. Many native fruits naturally exist at your elevation, including bright red wax currants (Ribes cereum), which have delicious, tart red berries, serviceberry (Amelanchier alnifolia), boulder raspberry (Rubus deliciosus) and red elderberry (Sambucus racemosa). You might be able to find these in regional, specialty nurseries that sell natives. (Click here for a list of Colorado native plant sellers.)
“We have a short growing season here. I would like to get as big a head start as possible on my seedlings. I plan to start my seeds indoors but also have a pop-up greenhouse, and would like to know how early I can start seeds indoors (under lights) and then transfer to my garden before transplanting to the garden. I am interested most in times for tomatoes.” Question from Melissa of McDonough, New York
Answer: When planting tomatoes in areas with cooler, shorter summers, you need to consider the variety as well as starting/planting time. In general, it takes about six to eight weeks to yield ready-to-plant starts from seed. Using heat mats, keeping indoor conditions warm, and providing lots of light will hasten growth. Most tomatoes produce fruit between 60 to 85 days after planting, depending on the variety. Choose tomatoes that produce early and are shown to yield good-tasting fruits in cooler climates. Your average tomato colors up and gains its best flavor when days and nights are warm. You can’t count on these conditions further North, which is why the variety is important. (Click here on a full guide to growing tomatoes from seed to harvest.)
Good Tomato Varieties for Northern Gardens
‘Juliet’ (60 days, paste tomato): The award-winning’Juliet’ is a red paste or sauce tomato that also tastes great fresh. It grows quickly and will perform well for you.
These are just three of many early, cool-tolerant tomatoes you might consider.
Plant your finished tomato starts outdoors after the threat of frost has passed. Some eager tomato gardeners plant theirs earlier outdoors and protect plants with hoop covers and frost cloth. This is an option, but I find it safer to simply grow mine to a larger size indoors and then harden them off before planting. Your pop-up greenhouse sounds just perfect for the job.
“I’d like to grow Brussels sprouts in my garden for the first time this year. When do I plant, and how much water do they need?” Question from Amber of Bay City, Michigan
Answer: Brussels sprouts are a cool-season crop for fall. This means that they need cooler temperatures to grow well and set Brussels sprouts, and they do this best in the long, cool period of fall. In your northern zone, start plants from seed in early summer, and get them in the ground no later than August first. When starting plants from seed, it can take as long as two months to grow seedlings to planting size. You may also be able to purchase starts at your local garden center.