Which Plants Can You Feed with Tomato Feed? (And Which to Avoid)
Tomato feed is high-potash fertiliser by another name. Any plant that flowers and fruits benefits from extra potassium — but plants grown primarily for their leaves do not. This guide covers exactly which plants thrive on Tom-Sol™ tomato feed and which should be fed something different.
Why Tomato Feed Works on More Than Tomatoes
The reason "tomato feed" is good for so many plants is what's inside the bottle. Tom-Sol™ has an NPK ratio of 4-3-8 — meaning potassium (K) is the dominant nutrient. Potassium drives flowering, fruit set, fruit size, sugar content, and disease resistance.
Any plant where you want strong flowering or fruit production benefits from this nutrient balance. The plant doesn't know it's marketed as "tomato feed" — it just receives the high-potash nutrition it needs.
Plant-by-Plant Guide
Each plant below is rated for whether Tom-Sol™ is suitable, plus brief notes on timing and dilution.
| Plant | Verdict | How to feed |
|---|---|---|
| Tomatoes | ✓ Ideal | 15ml per 4.5L water, weekly from second truss set, twice weekly in peak summer if drying fast. |
| Peppers (sweet & bell) | ✓ Ideal | Same nightshade family as tomatoes — identical dilution and frequency. |
| Chillies | ✓ Ideal | Weekly from second truss set. High potash supports heat development and ripening colour. |
| Aubergines | ✓ Ideal | Same nightshade family. Weekly feeds support the heavy fruit set aubergines produce. |
| Roses | ✓ Excellent | Fortnightly from May–September during flowering. Potassium drives stronger blooms and disease resistance. |
| Hydrangeas | ✓ Excellent | Fortnightly through the flowering season. Particularly helpful for repeat-flowering varieties. |
| Cucumbers | ✓ Good | Begin once first cucumbers form. Apply every 10–14 days through the cropping season. |
| Courgettes | ✓ Good | Begin once flowering starts. Fortnightly feeds support the heavy fruit production. |
| Melons & squashes | ✓ Good | Fortnightly once flowering. High potash improves sweetness and fruit development. |
| Strawberries | ✓ Good | Fortnightly during fruiting season. Improves fruit size and natural sugar levels. |
| Raspberries & soft fruit | ✓ Good | Fortnightly during fruiting. Supports fruit development without excess leafy growth. |
| Sweet peas & flowering annuals | ✓ Good | Fortnightly during peak flowering. Encourages stronger blooms and longer flowering window. |
| Dahlias | ✓ Good | Fortnightly through the flowering season. Strengthens stems and improves bloom size. |
| Lettuce | ✗ Avoid | Leafy crop — wants nitrogen, not potassium. Use a balanced general feed instead. |
| Spinach & chard | ✗ Avoid | Grown for leaves. Tomato feed would push flowering at the expense of leaf production. |
| Herbs (basil, parsley, coriander) | ✗ Avoid | Grown for soft leaves. High potash promotes early flowering which spoils flavour. |
| Lawns | ✗ Avoid | Grass wants high nitrogen for green growth. Use a dedicated lawn feed. |
| Brassicas (cabbage, broccoli, kale) | ⚠ Caution | Want nitrogen until heads form. Low-rate Tom-Sol may help broccoli/cauliflower heads — but use sparingly. |
| Seedlings & young plants | ✗ Avoid | Need balanced nutrition for early growth. Wait until plants are established and flowering. |
The Underlying Rule
If you want to remember the rule without memorising every plant, it's this: tomato feed is for what the plant produces above the leaves — flowers, fruit, seeds, and edible pods. It is not for the leaves themselves.
- Plants you eat for the fruit or flowers → tomato feed is appropriate.
- Plants you eat for the leaves → use a balanced or nitrogen-led feed instead.
- Plants you grow for the display flowers → tomato feed is excellent.
- Plants in early growth before flowering → wait until they flower before switching to tomato feed.
What to Use Instead for the "Avoid" Plants
For the plants in the "avoid" column above, a balanced general-purpose liquid feed or a high-nitrogen specialist feed (for leafy crops and lawns) is the right choice. The nutrient need is different — there is no single feed that suits every plant.
Tom-Sol™ Tomato Feed — high-potash NPK 4-3-8 with chelated calcium, magnesium and natural seaweed extracts.
Order Tom-Sol™ Tomato Feed →
