The best advice I can offer is that repellents can help, but must be rotated and reapplied frequently, and physical barriers remain the most reliable protection. The following list of repellents that are recommend for discouraging deer from eating tomatoes.

Egg based order repellants such as “Deer Away” or “Deer Stopper” work because they mimic predator scents and trigger avoidance behavior in deer. Also, a quick search of the Internet will supply many homemade putrescent egg solids formulas to try. Just be sure if your purchase a repellant spray that it is labeled for use on edible crops, Apply the repellant to the stake or around the tomato bed.

Hot pepper (Capsaicin) repellants irritate the deer’s mouth and discourage repeated feeding. Again, a quick search of the Internet will yield many formulas containing hot peppers.

Dried or liquid predator (coyote, wolf) urine relies on the deer avoiding any predator’s scent. This repellant can be spread around the tomato bed.

The downside of any of these repellants is that they have a strong order. Rotate these repellants every two or three weeks to prevent deer habituation. Reapply any repellant after rain as most repellents lose effectiveness when washed off. Use repellents as part of a multi‑layer strategy, not as the sole method. If you purchase a repellant, make sure it is labeled for edible crops. Combine repellents with physical barriers (netting, fencing, cages) for tomatoes, which deer find highly palatable.

The most effective way to prevent deer damage to edible crops is a physical barrier. Either a seven foot fence around the entire garden or hardware cloth or plastic netting wrapped around the tomato cages.

Michigan State University Extension Service has an excellent tip sheet titled “Smart Gardening to Deter Deer” the tip sheet can be downloaded here: Smart Gardening to Deter Deer - Gardening in Michigan

Thank you for your question and have a great gardening seasons.