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Walk into any garden center in spring and you’ll see tomato plants labeled “determinate” or “indeterminate.” Or sometimes just mysterious letters like “I” or “D.”
What the hell does that mean? And why does it matter?
Turns out, it matters A LOT. Choose the wrong type for your situation and you’ll be frustrated all season. Choose the right type and gardening gets way easier.
Let me break down the difference in plain English.
## The Simple Explanation
Determinate tomatoes: Bush-type plants that grow to a set height (usually 3-5 feet), produce all their fruit within a few weeks, then stop.
Indeterminate tomatoes: Vining plants that keep growing taller all season (6+ feet is common, some reach 10+ feet), producing fruit continuously until frost kills them.
## Determinate Tomatoes: The “Set It and Forget It” Type
Think of determinates as the responsible, predictable friend. They have a plan and they stick to it.
### How They Grow:
– Reach a predetermined height (usually 3-5 feet)
– Stop growing taller once they set fruit
– All flowers bloom around the same time
– All fruit ripens within a 1-2 week window
– Then they’re done for the season
### Common Determinate Varieties:
– Roma
– Celebrity
– Bush Early Girl
– Patio Princess
– Rutgers
– Mountain Fresh
– Better Bush
### Best For:
– Canning and preserving: Get a big harvest all at once
– Small spaces: Compact, manageable size
– Containers: Most don’t need heavy support
– Short growing seasons: Mature faster
– Beginners: Less pruning, less maintenance
### Pros:
✅ Compact size (easier to manage)
✅ Less or no pruning needed
✅ Great for containers
✅ Produce big harvests all at once (perfect for sauce/canning)
✅ Easier to stake (shorter plants)
✅ Work well in small gardens
### Cons:
❌ Shorter harvest window (1-2 weeks, then done)
❌ Lower total yield per plant over the season
❌ Not great if you want fresh tomatoes all summer long
❌ If something goes wrong during their production window, you might lose most of your harvest
## Indeterminate Tomatoes: The “Keep On Trucking” Type
Indeterminates are the overachievers. They don’t know when to quit (literally—frost has to kill them).
### How They Grow:
– Keep growing taller all season (vining habit)
– Continuously produce new flowers and fruit
– Fruit ripens gradually over months
– Keep producing until frost or disease stops them
– Can reach 6-10+ feet tall
### Common Indeterminate Varieties:
– Brandywine (most heirlooms are indeterminate)
– Cherokee Purple
– Better Boy
– Early Girl
– Big Beef
– Most cherry tomatoes (Sungold, Sweet 100)
– Black Krim
– San Marzano
### Best For:
– Fresh eating all summer: Continuous harvest
– Large gardens: Room for tall plants
– Maximum yield per plant: Produce more overall
– Tomato fanatics: You want ALL the tomatoes
– Long growing seasons: Can produce for 3-4+ months
### Pros:
✅ Continuous harvest all season
✅ Higher total yield per plant
✅ Fresh tomatoes from July through October
✅ Usually better flavor (especially heirlooms)
✅ You’re never without tomatoes
### Cons:
❌ Need significant support (tall stakes or cages)
❌ Require pruning for best results
❌ Can become unmanageable without maintenance
❌ Take up more space
❌ Not ideal for preserving (fruit ripens gradually, not all at once)
## How to Tell Which Type You Have
Check the seed packet or plant tag: Should say determinate or indeterminate (or use abbreviations like “D” or “I”).
Look at growth habit:
– Compact, bushy, sets fruit clusters all at once: Determinate
– Keeps getting taller, sprawls, continuous flowering: Indeterminate
Plant height:
– Stops at 3-5 feet: Probably determinate
– Grows to 6+ feet or more: Definitely indeterminate
Still not sure? Google the variety name. There are databases listing whether tomatoes are det or indet.
## Semi-Determinate: The Middle Ground
Some varieties are labeled “semi-determinate.” These are hybrids that:
– Grow larger than determinates but shorter than indeterminates (4-6 feet)
– Produce over a somewhat extended period
– May benefit from light pruning
Examples: Celebrity, Mountain Fresh Plus
Treat them like compact indeterminates—light pruning, moderate support.
## Care Differences
### Supporting:
Determinates:
– Small tomato cages (3-4 feet tall) usually sufficient
– Or simple stakes
– Some compact varieties don’t need support at all
Indeterminates:
– Need tall, sturdy cages (5-6+ feet) or strong stakes
– May need to be tied as they grow
– Can be grown on trellises or strings
### Pruning:
Determinates:
– Minimal pruning (only remove diseased/damaged leaves)
– DON’T remove suckers—you’ll reduce yield
– Remove lower leaves for airflow once established
Indeterminates:
– Remove suckers regularly to manage growth
– Prune lower leaves for disease prevention
– Can be trained to 1-2 main stems
– Topping (removing growing tip) 4-6 weeks before frost helps ripen remaining fruit
### Spacing:
Determinates:
– Can plant closer together (18-24 inches apart)
– Work well in raised beds and containers
Indeterminates:
– Need more room (24-36 inches apart, more for sprawling types)
– Air circulation is critical to prevent disease
### Feeding:
Determinates:
– Feed at planting and maybe once mid-season
– They’re done quickly, so less feeding needed
Indeterminate:
– Feed regularly throughout the season (every 2-3 weeks)
– They’re growing machines that need constant fuel
## Which Should YOU Grow?
### Grow Determinates If:
– You want tomatoes for canning/sauce/preserving
– You have limited space (small garden, patio, balcony)
– You’re growing in containers
– You want less maintenance
– You’re a beginner
– You have a short growing season
– You don’t want to deal with pruning
### Grow Indeterminates If:
– You want fresh tomatoes all summer long
– You have space for large plants
– You’re willing to prune and maintain
– You want maximum yield per plant
– You love the flavor of heirlooms (most are indeterminate)
– You have a long growing season
– You don’t mind staking and trellising
### Grow Both If:
You’re smart! This is what I do.
The strategy:
– Plant 2-3 determinates for a big harvest to can/freeze/make sauce
– Plant 3-4 indeterminates for continuous fresh eating
Best of both worlds!
## Common Varieties by Type
### Determinate:
– Paste tomatoes: Roma, Amish Paste (actually semi-determinate), Juliet
– Slicers: Celebrity, Bush Early Girl, Mountain Fresh, Rutgers
– Container varieties: Patio Princess, Tiny Tim, Bush varieties
### Indeterminate:
– Heirlooms: Brandywine, Cherokee Purple, Black Krim, Green Zebra, Mortgage Lifter
– Hybrids: Better Boy, Big Beef, Early Girl, Beefsteak
– Cherry tomatoes: Sungold, Sweet 100, Black Cherry
## Productivity Comparison
Determinate:
– Produces 10-20 pounds per plant over 1-2 weeks
– All at once (great for preserving)
Indeterminate:
– Produces 20-40+ pounds per plant over 3-4 months
– Continuously (great for fresh eating)
Winner: Depends on your goal! For total yield, indeterminate. For concentrated harvest, determinate.
## Can You Mix Them in One Garden?
Absolutely! In fact, it’s a great strategy.
Tips for mixing:
– Plant determinates in front (they’re shorter and won’t shade other plants)
– Plant indeterminates in back or center
– Group by type for easier maintenance (all indeterminates together, all determinates together)
## Troubleshooting
“My determinate plant keeps growing!”
It might actually be indeterminate. Check the variety. Or it could be semi-determinate.
“My indeterminate stopped growing.”
Check for disease, pests, or environmental stress. Indeterminates should keep growing until frost (or until they die of disease, unfortunately).
“Can I make an indeterminate behave like a determinate?”
Sort of. Aggressive pruning and topping can limit size, but it goes against the plant’s nature.
## The Bottom Line
Determinate vs. indeterminate isn’t just garden jargon—it fundamentally changes how you grow, support, prune, and harvest your tomatoes.
Quick decision tree:
– Want sauce/canning → Determinate
– Want fresh tomatoes all summer → Indeterminate
– Small space/containers → Determinate
– Have room and time for maintenance → Indeterminate
– Beginner → Start with determinate, try indeterminate next year
– Love heirloom flavor → Indeterminate (most heirlooms are)
Or just do what I do: grow both and have tomatoes coming out your ears all season long.
Now go check those plant tags and figure out what you’re actually growing! 🍅
