VCR – Vegetable Crop Report – June 4th, 2026

Crop Updates

Brassica Crops – Transplants are starting to take off in fields that were planted in late April or early May. Cabbage maggot has reached its first-generation threshold in Southern regions like Lambton, Chatham-Kent, Middlesex and Norfolk counties. Dig up wilted transplants, even in dry areas, to inspect roots for maggots. Cutworm damage is being found in many different crops and Brassicas are no exception. Products registered for cutworm management are most effective when they are applied early when the cutworm larvae are small. Damage found on the lower leaves of plants with no sign of lepidopteran pests may be the result of early-morning slug feeding, especially around field edges. Stunted plants with red leaves and girdled crowns are likely due to wirestem / Rhizoctonia infection.

Garlic – Be on the lookout for leek moth damage as hardneck cultivars are scaped over the next two weeks. Refer to this article for managing leek moth: https://onvegetables.com/2025/03/07/leekmoth-3/. Snap scapes above the newest leaf and avoid using sickle bar mowers or any knife to remove scapes, as they can easily spread garlic pathogens (including viruses) and often damage leaves during the scape removal process. Past research by John Zandstra has shown that by accidentally removing one leaf when the scape was removed, bulb sizes were reduced by 13% and the yield was reduced by an average of 17.5%. The same trial showed that yield was greatly impacted as the number of leaves cut during mowing increased. If the top two leaves were cut, the yield was reduced by approximately 25%, almost outweighing any potential gains you would expect by removing the scape in the first place.

Register for the Garlic Growers Association 2026 field day this Saturday, June 6th at Great Lakes Family Farms near Grand Bend, Ontario. Equipment from multiple manufacturers will be on display, along with products from fertilizer and pest control product suppliers. The agenda includes presentations on results from past garlic trials, industry, and minor use updates as well as a tour of a new garlic curing and storage facility. Registration starts at 9:00, the agenda starts at 9:30 and goes until 4:30. Lunch will be provided. Great Lakes Family Farms is located at 70748 B Line, Grand Bend, Ontario, and all are welcome to join, rain or shine. Please register for the field day by going to https://www.eventbrite.ca/e/field-day-2026-tickets.

**Figure 1**. An early scape emerging. Huron county – June 2^nd, 2026.

Onion – Direct seeded fields are between the flag and 4th leaf stage. Transplants are doing even better in fields where they have had enough moisture. Onion maggots were active the past couple of weeks. Be on the lookout for wilted plants and dig affected plants and look for maggots. Cutworm damage has been observed but is sporadic. Dig a few inches around plants that appear to have been cut with scissors and try to find the cutworm larvae around plants that have been cut. Insecticides targeting cutworms are more effective if the larvae are small and the damage is found early. A list of products registered to manage cutworms in onions can be found on the Ontario Crop Protection Hub.

Peppers – Pepper planting is ongoing. Growers should aware of European corn borer as the first peak has begun. Though the second peak will be more worrisome as the plants will have fruit at that time. There are many control options available for growers in need. Always make sure to read all product labels before any pest control product application.

Tomatoes – Tomato planting in ongoing but should be wrapping up soon. The recent warmer temperatures have done wonders for the earlier plantings and they are growing out of the chilling injury they suffered a few weeks ago. Growers should still be on the lookout for early season pests like Colorado potato beetle, cutworms and wireworms as the plants are still small enough to be damaged significantly by these insects.

Pest Degree Day Forecasting

County	Carrot Rust Fly	Onion Maggot	Carrot Weevil	Aster Leafhopper	Tarnished Plant Bug	Cabbage Maggot	Seedcorn Maggot	European Corn Borer
THRESHOLD	329-395, 1399-1711	210-700, 1025-1515	138-156, 455+	128+	40+	314-398, 847-960, 1446-1604	200-350, 600-750, 1000-1150	See legend below
Bruce***	356	300	157	87	30	200	300	61
Essex*	695	621	418	298	151	483	621	244
Chatham-Kent*	605	533	340	234	118	402	533	191
Norfolk**	542	475	308	216	106	358	475	174
Huron***	447	383	222	138	51	272	383	104
Wellington**	430	373	228	149	66	271	373	116
Simcoe County***	421	364	224	147	68	267	364	115
Durham***	465	405	253	170	84	300	405	137
Peterborough	446	387	241	164	76	287	387	130
Kemptville***	473	415	256	175	87	305	415	142
Sudbury***	289	247	149	100	46	179	247	79
Timiskaming***	261	220	135	91	42	158	220	73
Lambton**	536	466	287	197	87	342	466	157
Thunder Bay	207	169	89	57	24	110	169	44
Middlesex*	569	501	323	227	112	378	501	184
Renfrew	426	372	227	156	81	273	372	129