Last Updated on October 9, 2026

Soil pH for Vegetables Chart: 50+ Crops and Herbs

Most vegetables grow best at a soil pH of 6.0 to 7.0; aim for 6.5 in a mixed bed. Most cabbage-family crops, beets and asparagus need the pH kept up, with lime once it drops below 6.2. Potatoes, sweet potatoes, carrots, rhubarb and horseradish tolerate more acid and mostly call for lime only below 5.5, lower still for scab-prone potatoes. Test first, then raise a low pH with lime or wood ash.

Soil pH chart for vegetables and herbs

Read each row two ways. The first number column is the range a home garden guide gives for that crop. The second is the pH where a grower table says to add lime. Where a guide does not list a crop, the cell says so instead of guessing.

Home garden ranges: CCE = Cornell Cooperative Extension Vegetable Growing Guide; UMN = University of Minnesota Extension (potatoes, rhubarb, parsley, herbs, basil, chives, dill); VCE = Virginia Cooperative Extension, Herb Culture and Use; UT = University of Tennessee Extension; NC State = NC State Extension Gardener Handbook. Add-lime-below numbers: Table B-1 of the Mid-Atlantic Commercial Vegetable Production Recommendations, except the rows marked Cornell, which use the minimum pH in Cornell’s nutrient guidelines for vegetables.

A caution on that last column. Both grower tables were written for commercial farms, and the Mid-Atlantic guide states plainly that its recommendations are not for home gardener use. This chart uses them only to compare one crop with another. Your own soil test sets how much lime your bed gets.

What the chart means for your beds

• A mixed bed: aim for 6.5. The Mid-Atlantic table gives mixed vegetables a target of 6.5 and adds lime below 6.0, and Cornell University calls 6.0 to 7.0 optimal for most vegetables.
• A cabbage-family bed: keep it at 6.2 or higher. Cabbage, broccoli, kale and the other cole crops get lime at 6.2 on the grower tables, sooner than tomatoes and squash at 6.0.
• A potato bed: leave it on the acid side. Cornell Cooperative Extension says potatoes, unlike most vegetables, tolerate acid soil. The grower target for scab-prone varieties is just 5.2, and UNH Extension says not to give them wood ash unless a soil test recommends it.
• Herbs: most do fine anywhere from 6.0 to 7.5, and lavender and rosemary take the high end.

How to test soil pH: lab or kit

Use a lab if you can. A soil testing lab is more accurate than a home kit, according to University of Maryland Extension, and the report comes back with pH, nutrient levels and amendment recommendations. A kit will show you the number, but not how much lime to add: texture, organic matter and clay all change that amount, so the lab does the math for you. If you are filling a new bed first, the raised bed soil calculator and compost ratio calculator can help you get the mix right before you test.

NC State Extension‘s guide covers how to take a good sample:

1. Use a clean plastic bucket and a stainless steel or chrome-plated trowel. Brass, bronze or galvanized tools can contaminate it.
2. Dig a hole and slice soil down one side, to the depth you work the bed.
3. Repeat in five to eight spots and mix them into one sample. Skip wet spots, compost piles and burn spots, and pick out roots and leaves.
4. Send about a pint. Sample the vegetable garden separately from the lawn and flower beds.

Repeat the test every two to three years, and test at the same time of year each time. pH typically reads 0.3 to 0.5 unit higher in spring than during the growing season, according to Oregon State University Extension.

How pH changes what your plants can use

pH controls which nutrients your plants can pull out of the soil. The scale is logarithmic: 6.0 is ten times more acidic than 7.0, and 5.0 is a hundred times more acidic. The best phosphorus uptake is between 6.0 and 7.0, according to University of Vermont Extension: in acid soil phosphorus binds with aluminum and iron, and in high-pH soil it binds with calcium.

Acid soil frees up iron, manganese, zinc and copper, and below about 5.5 those same minerals, plus aluminum, can reach toxic levels. Calcium, phosphorus and magnesium are less available at low pH, and above 6.5 phosphorus and most micronutrients become less available too, according to Clemson Extension.

How to raise soil pH with lime

1. Use the rate on your soil test. Lab reports give pounds per 1,000 square feet. Scale that to your bed: rate times bed area, divided by 1,000. A 4×8 bed is 32 square feet, so a 50-pound rate becomes 50 x 32 / 1,000 = 1.6 pounds.
2. Pick the type. Dolomitic lime carries magnesium and suits soil that runs low in it; calcitic lime suits soil that already has plenty.
3. Time it. Apply limestone two to three months before planting so it has time to work. Count back from your last frost date if you are liming in spring.
4. Work it in, or split it. Fall after harvest is the best time, with the lime mixed into the upper 4 to 6 inches. When the rate is large, such as 20 pounds per 100 square feet, mix half in the fall and half in spring.
5. Be patient, then retest. Lime may take one to three years to reach its full effect, and over-liming can cause iron chlorosis. Test again before adding more.

These steps follow soil-test guidance from NC State Extension, Clemson Extension, Cornell and Nebraska Extension.

In my raised beds I do not turn the soil. I top-dress compost and let the worms do the mixing. For a no-dig bed, the same NC State rule for established gardens fits: spread up to 50 pounds per 1,000 square feet on the surface at one time, and wait several months before a second dose. That is the same 1.6 pounds on a 4×8 bed.

Liming is not a one-time job: rain leaches calcium and magnesium out of the soil, and decomposing organic matter adds a little acid, so pH drifts back down, according to Clemson Extension. Sandy soil resists pH change less than clay, so it takes less lime to move.

Wood ash: faster, but easy to overdo

My grandfather put wood stove ash on his garden, and I adopted his method when I started growing organically. Wood ash is very alkaline, about 10 to 12 on the pH scale, so it raises the pH of acid soil. The rule in my wood ash guide: sprinkle a thin layer at the end of the season or several weeks before planting, rake it in lightly, and limit it to 5 pounds per 100 square feet.

UNH Cooperative Extension gives the numbers behind that caution:

• Ash changes pH faster than ground limestone, but it takes 2 to 4 times as much ash to get the same change.
• A 1,000-square-foot garden already at pH 6.5 needs no more than 20 pounds of ash, about a five-gallon bucket. That is 2 pounds per 100 square feet.
• Mix it into the top 2 to 4 inches, and keep it off germinating seeds; the salts hurt germination.
• Skip it on blueberries and scab-prone potatoes unless a soil test says otherwise.
• Ash is caustic. Wear gloves and eye protection, and never use ash from garbage, painted or pressure-treated wood.

Quick questions

What is the best soil pH for vegetables?

Most vegetables grow best between 6.0 and 7.0, according to Cornell University. For a bed of mixed vegetables, the Mid-Atlantic grower guide sets a target of 6.5 and calls for lime when the pH falls below 6.0.

Which vegetables like acidic soil?

Potatoes, sweet potatoes, carrots, rhubarb and horseradish tolerate the most acid. The grower table only calls for lime on them below pH 5.5, and Cornell Cooperative Extension notes that potato scab is suppressed at pH 4.8 to 5.5.

Which vegetables like alkaline soil?

Asparagus is the standout: NC State Extension says it can tolerate a pH up to 8.0. Cornell Cooperative Extension lists broccoli, Brussels sprouts and bok choy at 6.0 to 7.5 and says they can tolerate slightly alkaline soil, and University of Tennessee Extension says lavender and rosemary do well above 7.0.

Can I use wood ash instead of lime?

Yes, in small amounts. UNH Cooperative Extension says wood ash works faster than ground limestone but takes 2 to 4 times as much for the same change, and a garden already at pH 6.5 needs no more than 20 pounds per 1,000 square feet. My limit is 5 pounds per 100 square feet, and none on acid lovers like blueberries.

How do I lower soil pH in a vegetable garden?

Stop adding lime and wood ash, then ask your local extension office what to use for your soil. Oregon State University Extension notes that lowering pH takes much longer than raising it, often several years.

Let the planner place them

Bed soil set, now place the crops. Plan My Garden is free to start: enter your zip code, draw your beds, pick the brassicas, potatoes, herbs and everything else you want to grow, and it places each plant at square-foot spacing and builds a planting schedule from your frost dates.

Related: How to Use Wood Ash in the Garden · Raised Bed Soil Calculator · Compost Ratio Calculator · Spring Garden Prep: Reset Your Raised Beds