Fertiliser
Organic Tomato Feed 3-4-6 | Slow-Release Tomato Plant Food
A slow-release 3-4-6 feed for tomatoes.
from £11.50
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I'm impressed. I already see a difference in my Autumn onions and they have perked up quite nicely. Good delivery times.
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High Nitrogen Fertiliser: 13% N plant-based granules for leafy growth
High Nitrogen Fertiliser is a 13% nitrogen granule made from fermented plant sugars, with the nitrogen held in amino acids and proteins rather than as a mineral salt. Roughly half becomes available in the first fortnight and the rest over the following weeks, so one dressing feeds for around six weeks. Use it for leaf and stem: brassicas, leafy veg, sweetcorn and lawns.
- Greens up hungry crops. Brassicas, leeks, sweetcorn, courgettes and salads put on leaf on nitrogen.
- Fast start, slow tail. About half the nitrogen in two weeks, the rest over the next month or so, so there is less to wash out between feeds.
- Sulphur in the same granule. Plants need sulphur to use nitrogen well; this carries both.
- Low salt, low chloride. Less risk of scorch and salt build-up than a synthetic salt feed, at the rates on this page.
- Plant-based. No animal meals. Vegan, low odour, 3 mm granule.
13% N
Plant-based
Feeds about 6 weeks
20–55 g per m²
High in sulphur
Vegan
Part of our nitrogen fertilisers. For nitrogen in a watering can, see Liquid Nitrogen Fertiliser 10% N.
What's in High Nitrogen Fertiliser
Plant protein nitrogen extract (100%)
Amino-acid and protein nitrogen drawn off fermented plant sugars (molasses) and dried into a 3 mm granule. 13% N, with sulphur, organic carbon and trace elements carried through from the plant source.
How to use High Nitrogen Fertiliser: rates for beds, lawns and pots
A little goes a long way
This is a concentrated 13% nitrogen feed, so it is used at much lower rates than a balanced blend or a soil conditioner. Scatter the granules evenly, keep them off leaves and stems, and water in well. Apply to moist soil during active growth. Less, more often, beats one heavy dose.
How much, and how often
One application feeds for around six weeks: roughly half the nitrogen releases in the first fortnight, the rest over the following weeks. Because of that, do not reapply more often than every five to six weeks. Across all uses, a single dressing sits between 20 and 55 g per m² (a rounded handful is roughly 30–40 g). Match the rate to how hungry the crop is, using the guide below.
Base dressing — before sowing or planting
Scatter over the bed and rake or fork lightly into the top 5–10 cm a few days before sowing or planting leafy and hungry crops. Use the lower rate on already-fertile soil, the higher rate where growth has been weak or the bed is freshly dug.
Heavy nitrogen feeders — top dressing
The hungriest leafy crops: brassicas (cabbage, cauliflower, calabrese and broccoli, Brussels sprouts, kale), leeks, sweetcorn, courgettes, squash and pumpkins, rhubarb, and spinach and chard. Scatter around the plants, keep granules off the foliage, work in lightly and water in. Two to three feeds across the season is usually plenty; stop once growth is strong and well coloured.
Salad and moderate leafy crops — top dressing
Lettuce and salad leaves, beetroot and chard tops, leafy herbs, and any plant showing pale lower leaves or slow, stalled growth. Lighter, more frequent feeding suits fast salad crops better than one heavy dose.
Established lawns
Spread as evenly as you can on a still day and water in well. The fast fraction greens the lawn up, the slow tail keeps it fed for weeks. Avoid applying in drought or to dry turf, and stop feeding nitrogen by late summer so you are not pushing soft growth into autumn.
New lawns and overseeding
For a new lawn, work into the top 5 cm of the prepared seedbed before sowing or laying turf. For overseeding, scatter over the area after seeding and water in thoroughly. The slow release feeds through establishment without scorching young roots.
Fruiting crops — early stage only
Tomatoes, peppers, chillies, aubergines, beans and peas need nitrogen only to build their early leaf framework. Feed during vegetative growth, then stop at first flower and switch to a high-potash feed such as Sulphate of Potash, or too much nitrogen pushes leaf at the expense of fruit.
Roses and flowering shrubs — spring nudge
A single spring application drives strong early foliage. Follow with a balanced or high-potash rose feed for the flowering flush, and avoid further nitrogen later in the season.
Pots and containers
Mix into the compost when potting up leafy plants, or lightly top-dress established pots and water in. Containers hold a small soil volume, so keep to the lower rate and do not over-feed.
Easy to overdo — don't
Even with a low salt index, too much nitrogen drives soft, sappy growth that flops and resists flowering and fruiting; very heavy doses on dry soil can scorch. Stick to the rates above, water in, and reach for a balanced feed once leafy growth is established.
Step by step
- Measure. A level tablespoon is roughly 15–20 g. Weigh the first few applications until you have your eye in.
- Scatter evenly. Spread thinly across the area or around the base of plants. Keep granules off leaves, stems and crowns.
- Work in lightly where you can — a shallow rake or hoe on beds; for established plants and lawns, leave on the surface.
- Water in well. Moisture starts the release and moves the first nitrogen down to the roots. If no rain is forecast within 48 hours, water the area to help the granules break down and prevent scorch.
- Repeat on schedule — no more often than every five to six weeks — through the growing season, then taper off as plants move into flower and fruit. On light, sandy soils, split feeds and keep to the lower rates. Store sealed, cool and dry.
How High Nitrogen Fertiliser works
- Roots can take up amino acids. Plants carry transporters for amino acids and short peptides and absorb some intact; the rest is released by soil microbes [Näsholm et al. 2009].
- Protein-bound nitrogen is slower to leave. Nitrate leaches readily and urea can be lost to the air as ammonia; nitrogen held in protein stays put until biology releases it [Cameron et al. 2013].
- Nitrogen needs sulphur. Both go into proteins and chlorophyll, and a sulphur shortfall limits how well plants use the nitrogen they take up [Marschner 2012].
References
- Cameron, K.C., Di, H.J. & Moir, J.L. (2013). Nitrogen losses from the soil/plant system: a review. Annals of Applied Biology, 162, 145–173.
- Marschner, H. (2012). Mineral Nutrition of Higher Plants (3rd ed.). Academic Press. [nitrogen and sulphur nutrition]
Figures from published research are not a trial of this product.
Use High Nitrogen Fertiliser with
- Organic All Purpose Fertiliser 4-4-4: a balanced feed once leafy growth is established.
- Sulphate of Potash: the potash fruiting crops want once they reach first flower.
- Scottish Kelp Meal: trace elements a straight nitrogen feed doesn't carry.
Which to choose: these granules feed for weeks from one dressing. Liquid Nitrogen Fertiliser 10% N is for a quick watering-can feed, and the Organic Lawn Fertiliser 10-3-3.5 is made for turf.
High Nitrogen Fertiliser FAQs
A single dressing is 20 to 55 g per m², and a rounded handful is roughly 30 to 40 g. Bed preparation: 30–50 g per m² once. Hungry crops: 40–55 g per m² every 5–6 weeks. Salads: 25–40 g per m² every 5–6 weeks. Lawns: 25–40 g per m², once or twice, 6–8 weeks apart. Pots: 2–4 g per litre of compost.
Roughly half the nitrogen is available within about a fortnight, so leafy green-up often shows in one to two weeks in active growth. The rest releases over the following weeks. Don't reapply more often than every five to six weeks.
It is a plant-based nitrogen feed from fermented plant sugars, not a synthetic ammonium nitrate or urea salt. It is not certified organic.
Only early on: 20–30 g per m² once or twice before flowering. Stop at first flower and move to a potash-led feed, or the plant puts on leaf at the expense of fruit.
It has a low salt index, but it is still 13% N. Very heavy doses on dry soil can scorch, and too much nitrogen gives soft, floppy growth. Keep to the rates, apply to moist soil and water in.
Pale or yellowing older leaves first, slow growth and thin stems. Check watering, compaction and cold soil before blaming the feed. If the yellow sits between green veins, look at magnesium instead.
No. Epsom salt is magnesium sulphate, with no nitrogen.
Yes. The nitrogen comes from fermented molasses, with no animal meals.
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