Leek
Companion plants for leeks
The best companion plants for leeks are celery, tomatoes, cabbage, carrots and onions. Swiss chard is best kept away. Of the 9 plants we have data on, 5 are good neighbours, 1 is a bad one and 1 is contested. 4 of these verdicts rest on field trials or research papers; the rest come from traditional companion-planting charts.
- 5 good
- 1 to avoid
- 1 contested
- 4 tested in trials or papers
Neighbours of leeks at a glance
Inner rings are backed by trials or papers, outer rings by charts only. Pick a plant to see its sources.
The interactive map needs JavaScript. Every plant on it is listed below with its evidence.
Good companion plants for leeks
Biggest harvest gain first, then the plants tested without a yield count. Each row links to the full evidence for the pair.
| Plant | What trials found with leeks | Tested by | Garden charts |
|---|---|---|---|
 Celery |
Less competition19% more harvest from the same space | Field trial2 studies | Recommend |
 Cabbage |
16% more harvest from the same space | Field trial1 study | Not listed |
 Tomato |
Less disease and better soil and nutrient uptake | Greenhouse or pot trial2 studies | Recommend |
Harvest from the same space compares a bed with both crops against the same area split into single-crop beds, counting the harvest of both crops (the land equivalent ratio in yield trials).
Recommended by garden charts, not tested yet
We found no trial or paper on these pairs with leeks. They may still work; nobody has measured it.
What not to plant with leeks
| Plant | What trials found with leeks | Tested by | Garden charts |
|---|---|---|---|
 Swiss chard |
No trial found | Not tested | Advise against |
Relatives that share pests and diseases
| Plant | What trials found with leeks | Tested by | Garden charts |
|---|---|---|---|
 Garlic |
No trial foundSame family (Amaryllidaceae): shares pests and diseases | Not tested | Not listed |
 Chives |
No trial foundSame family (Amaryllidaceae): shares pests and diseases | Not tested | Not listed |
Contested pairings
The sources disagree, or the charts say one thing and the trials another. Open a pair before you plant it.
| Plant | What trials found with leeks | Tested by | Garden charts |
|---|---|---|---|
 Sweet corn |
Mixed results on pests | Field trial1 study | Not listed |
Sources
8 sources behind the verdicts on this page. 7 chart entries cite no source and are marked as tradition only.
What grows well with your leeks?
Share what worked next to your leeks and what did not, or ask other growers a question. Reader notes are not checked by us and do not change the verdicts on this page.