By Larry Hodgson
Carrots (Daucus carrot) are not the easiest vegetables to grow. Anyone whose says they are is doing a bit of wishful thinking. They’re slow and often irregular in sprouting, only do well in really good soil, won’t tolerate any dryness when young and have a couple of serious pest problems, including carrot flies.
Here are some tips on getting the best possible results from a rather finicky vegetable.
1. Provide Full Sun
What else did you expect? Pretty much all vegetables need it—at least 6 hours a day while 8 is even better—and carrots are no exception.
2. Prepare the Soil
Carrots need deep, rich, well-drained, stone-free soil. Raised beds often give the best results, as they’ve generally been filled with quality topsoil with no stones whatsoever. If you garden “in the ground,” you need to get the stones out to a depth of at least 1 foot (30 cm). If not and the roots hit an obstacle, they’ll be forked or deformed. If you’re into no-till gardening and are dealing with heavy clay soil, at least use a garden fork to work in organic matter like compost to lighten the soil. (And repeat that yearly.)
3. Don’t Overfertilize
Yes, carrots love rich soil, but there’s a limit. So, you can work in compost and basic all-purpose organic fertilizer, but avoid ones rich in nitrogen (the first number) as well as overly fresh manure. Too much nitrogen will give great tops, but poor, spindly roots.
4. In Heavy Soil, Choose the Right Carrots.
Carrots with rounded rather than pointed tips, like Nantes or Chantenay types, do better in heavy soil than Imperator or Danvers types. If your soil is heavy and shallow, use dwarf carrots (round ones, for example). Since the soil needs to be nearly twice as deep as the root is long, if you garden in containers that aren’t at least 18 inches (45 cm) deep, also consider shorter carrots.
5. Consider Delaying Sowing
You’ll hear that you can sow carrots early, when the soil reaches about 50˚F (10˚C). When the grass needs mowing, some people say. True enough, but germination will be slow, irregular and probably poor in cool soil. Expect to wait about 3 weeks for seedlings to appear. If you wait about a month longer before sowing, germination will be faster (about 2 weeks) and more regular. And you can continue to sow with great success until about 8 weeks before the first fall frost, often into August.
6. Water Well and Keep Moist
From sowing until good growth starts, carrots are incredibly sensitive to dry conditions. Water thoroughly the day before you sow to make sure the soil is moist through and through, then, after sowing, water softly, so as not to disturb the seeds. Keep the soil near the surface slightly moist after that; at least until the leaves reach about 2 inches (5 cm) in height, as not only do the seeds need moisture to sprout, but dry soil can harden into a crust the tender seedlings can’t break through. That can mean nearly daily light watering until the seeds sprout!
Floating row cover can help keep soil moist (see point 8). Or cover the row with a plank to prevent evaporation. If so, check every few days and remove the plank when the seeds sprout.
7. Sow Shallowly and Abundantly
Carrot seeds are tiny and very poor at breaking through heavy or crusted soil. Sow only about ¼ inch (5 to 8 mm) deep. Sow densely, about 2 seeds per inch (1 seed per cm), as germination is never perfect. You can thin the seedlings (yes, they are edible) to a spacing of about 1½-4 in (4–10 cm) when they’re an inch (2.5 cm) or so tall, using the wider spacing for the largest roots.
Helpful Hint: Some gardeners like to sow a radish seed every foot (30 cm) or so in a row of carrots as a marker. Radishes germinate rapidly and tell you where the still dormant carrot seeds are.
8. Use Floating Row Cover
This is my main secret to sprouting carrots. Immediately after sowing, cover the soil with floating row cover placed directly on the soil and water through the fabric. This helps protect the fragile seeds from being disturbed by overly strong sprays of water (and heavy rain!); plus the cover warms the soil for better germination (in spring) and keeps it cooler (in the heat of summer) because it keeps some of the sun off. Row cover also reduces evaporation and leaves the soil more evenly moist. It also keeps the dreaded carrot fly at bay and even offers a few degrees of frost protection if ever that is needed. (It may well be in cooler climates if you sowed early!) You can remove the row cover once the plants are up and growing strongly.
Helpful Hint: Another way of reducing carrot fly damage is to sow resistant varieties, like ‘Fly Away’ and ‘Resistafly’. There are other suggestions here.
9. Hand pull weeds while they’re still tiny.
Carrots just don’t cope well with competition, so you can’t allow weeds to take over. At first, you’ll have to pull back the row cover in order to weed (just put it back afterwards). Hoeing can seriously damage fragile young carrots, so if you use that method, be careful.
10. Mulch when the seedlings are up and growing
Use a light mulch, covering the soil up to 3 inches (10 cm) deep with it once the leaves are 4 inches (10 cm) tall. Mulch will keep the soil moister and cooler, stop weeds from germinating and cover the plant’s crown so it won’t be exposed to the sun and turn green and bitter.
With these tips in mind, you’ll be well on your way to growing the best carrots ever!