Gardening in Arkansas

Hardiness zones in Arkansas

Arkansas falls across four USDA hardiness zones: 7a, 7b, 8a, and 8b. A hardiness zone number is based only on the average coldest night your area sees each winter. It says nothing else about the climate. The zone range for the state runs from 7a up to 8b, a gap of about four half-zones. That span means winters across Arkansas vary enough that a plant hardy at one edge of the state may struggle at the other. The zone number says nothing about summer heat, rainfall, humidity, or soil type. Two gardens in the same zone can still need different care for those reasons. Data for this hub comes from 112 weather stations across the state. That is what lets the zone map narrow down to 7a through 8b rather than one single number. Use your zone to choose perennials, shrubs, and trees that can survive your coldest nights outdoors. For when to plant each year, rely on the frost dates below instead of the zone number.

• Zone 7a
• Zone 7b
• Zone 8a
• Zone 8b

Frost dates

A frost date is the day with a 50 percent chance of frost, used as a planning guide rather than a fixed rule. Across Arkansas, the first fall frost can arrive as early as October 20 or as late as November 18. That is nearly a month of spread, depending on where in the state you garden. In spring, the last frost can fall as early as March 10 or as late as April 15. That spring range covers about five weeks too. These ranges come from 112 weather stations across the state, each logging its own local pattern. If your spot tends toward the early side of the fall range, protect tender plants by mid-October to be safe. If it tends toward the late side, you likely have extra weeks before the first frost risk begins. The same idea applies each spring: wait until after your local last-frost window before setting out tender seedlings. Treat both dates as a window, not a switch, since frost can still strike outside the usual range in an unusual year.

Climate

Arkansas's growing season is the stretch between your last spring frost and your first fall frost. It ranges from 188 to 251 days depending on where you garden. That is a difference of more than two months between the shortest and longest growing windows in the state. The state's hardiness zones run from 7a to 8b, which reflects how much milder winters get as you move across Arkansas. A longer growing season generally lines up with a warmer zone and a wider gap between the two frost dates. This hub's figures come from 112 weather stations across the state. That is why you see ranges here instead of one single number for the whole state. No two spots in Arkansas share the exact same frost-free stretch. Treat the figures on this page as a starting point for your own location. Use the zone range to judge winter cold. Use the season length to judge how much time your plants get between frosts each year.

Season length

Knowing where your garden falls in that 188 to 251 day range helps you choose what to plant and when. Even the shorter end, 188 days, is more than six months to grow in. The longer end, 251 days, stretches that window by two more months. If your season sits nearer the short end, pick crops and varieties with a shorter time to harvest. If it sits nearer the long end, you have more room to start plants from seed outdoors instead of transplanting. Either way, count forward from your last spring frost and back from your first fall frost to find your own window each year.