Unit 3 (March): The spring flush — nettle, dandelion and minerals
The first forage of the year, the chemistry of plant minerals, and the honest version of a spring tonic.
guideUnit 3 (March): The spring flush — nettle, dandelion and minerals Urtica dioica — hand-drawn plate, stylised. Not for identification — use a field guide and verify with a second source before eating any wild plant.
March is the month the wild garden starts producing, and nettle and dandelion are the first things worth having.
The chemistry of plant minerals, honestly. Plants contain minerals, and plants also contain phytate, which binds iron, zinc, calcium and magnesium into insoluble complexes the gut cannot absorb. This is why a plant food's mineral content on a label is not the mineral you get.
Three practical consequences.
Fermentation degrades phytate and measurably raises mineral absorption. This is the reason fermentation is the preservation method with a nutritional argument, and it is the one technique in the handbook that improves what it preserves.
Cooking leaches minerals into the water. Cooking measurably lowered potassium and magnesium in tested wild greens, and the minerals went into the cooking liquid. So: do not boil the greens and throw the water away.
But for oxalate, the opposite is true. Boiling and discarding the water is exactly right for high-oxalate greens, because the oxalate goes into the water and the oxalate is what you want gone. Those two pieces of advice point in opposite directions and both are correct, because they are about different compounds.
The honest version of a spring tonic. Nettle in March is a genuinely nutritious green vegetable, high in minerals and protein for a leaf, and eating it is a good idea. Nettle tea is not a treatment for anaemia. Actual iron-deficiency anaemia needs a diagnosis and usually iron supplementation, because the iron in a leaf tea is both modest in quantity and poorly absorbed. The red flags for anaemia — breathlessness, chest pain, black stool — are medical.
Nettle leaf and nettle root are different medicines. The root has randomised trial evidence in benign prostatic hyperplasia. The leaf does not have that evidence, and the leaf is the spring vegetable.
What the studies found
Meta-Analysis2025PloS one
Optimal dose and duration of iron supplementation for treating iron deficiency anaemia in children and adolescents: A systematic review and meta-analysis.
Low-dose iron supplementation (<5 mg/kg/day) combined with treatment durations of either less than 3 months or more than 6 months, is optimal for improving Hb levels in children and adolescents with IDA.
The effects of oral ferrous bisglycinate supplementation on hemoglobin and ferritin concentrations in adults and children: a systematic review and meta-analysis of randomized controlled trials.
Ferrous bisglycinate shows some benefit over other iron supplements in increasing hemoglobin concentration and reducing GI adverse events among pregnant women.
Oral iron supplementation and anaemia in children according to schedule, duration, dose and cosupplementation: a systematic review and meta-analysis of 129 randomised trials.
Weekly and shorter duration iron supplementation at moderate or high doses might be optimal approaches for children and adolescents at risk of deficiency.
Meta-Analysis2022Mini reviews in medicinal chemistry
Effects of Urtica dioica on Metabolic Profiles in Type 2 Diabetes: A Systematic Review and Meta-analysis of Clinical Trials.
UD consumption may result in an improvement in levels of FBS, HbA1c, CRP, triglycerides, and SBP, but did not affect levels of insulin, total-, LDL-, and HDL-cholesterol, BMI, and DBP in patients with T2DM.
| Plant | Part | Now | Rule |
|---|---|---|---|
| Nettle | Young leaf | Yes — before flowering | Gloves; top few leaf pairs only |
| Dandelion | Young leaf | Yes — least bitter now | Clean ground only |
| Violet | Leaf and flower | Yes | Mild and safe |
| Chickweed | Aerial | Yes | Salad and poultice |
| Plantain | Leaf | From spring on | Not from verges |
Garden work
Lime if the test said to; do it now for spring planting
Direct-sow calendula, chamomile, borage as soon as the soil can be worked — they tolerate cold
Divide mint and lemon balm as they start into growth
Do not work wet clay soil — you will make brick
The foraging rules apply in full
Identify with certainty, by more than one method
Clean ground only — no verges, no sprayed ground, no field edges beside conventional agriculture
Take a third at most; leave the strongest plants
Nettle leaf and root are different medicines — know which you are taking
Preparation
Project: nettle soup and a cold infusion
Nettle soup — the classic spring dish
Young nettle tops, washed, no need to blanch separately — the cooking disarms the sting
Onion, potato, stock; add nettle in the last few minutes so it keeps its colour
Keep the cooking liquid and eat it — that is where the minerals went
Cold infusion of marshmallow root — the month's technique lesson
1-2 tablespoons dried root in 500 mL cold water, overnight
The liquid should be visibly slippery
Heat degrades mucilage, which is why the cold method is the correct one and the hot method is the common mistake
Nettle as a vegetable — blanch briefly, dress with butter or oil. Eat the water.
Dandelion root coffee — scrub, chop, roast until dark and fragrant, grind, brew
A note on oxalate — for spinach, beet greens and rhubarb, boil and discard the water. Different compound, opposite advice.
Cautions and interactions
Nettle tea is not an anaemia treatment. Iron-deficiency anaemia needs diagnosis and usually supplements.
Do not harvest old nettle leaf — the crystals irritate the urinary tract.
Nettle and dandelion are potassium-rich — a hyperkalaemia risk with ACE inhibitors, ARBs or potassium-sparing diuretics.
Harvest only from clean, untreated ground.
Never take a wild plant you cannot identify with certainty.
When this is not a self-care problem — get help
Breathlessness, chest pain, dizziness or black stool — possible anaemia or GI bleeding; medical assessment.
Nausea, vomiting, confusion or drowsiness after eating a wild plant — poison control and emergency care, with a sample.
Muscle weakness or palpitations on dandelion plus blood-pressure medication — possible high potassium; urgent assessment.
Optimal dose and duration of iron supplementation for treating iron deficiency anaemia in children and adolescents: A systematic review and meta-analysis. PloS one 2025; doi:10.1172/JCI76666 PubMed 39951396
Daily oral iron supplementation during pregnancy. The Cochrane database of systematic reviews 2024; doi:10.1002/14651858.CD004736.pub5 PubMed 39145520
The effects of oral ferrous bisglycinate supplementation on hemoglobin and ferritin concentrations in adults and children: a systematic review and meta-analysis of randomized controlled trials. Nutrition reviews 2023; doi:10.1093/nutrit/nuac106 PubMed 36728680
Oral iron supplementation and anaemia in children according to schedule, duration, dose and cosupplementation: a systematic review and meta-analysis of 129 randomised trials. BMJ global health 2023; doi:10.1016/S0140-6736(06)67962-2 PubMed 36849195
Effects of Urtica dioica on Metabolic Profiles in Type 2 Diabetes: A Systematic Review and Meta-analysis of Clinical Trials. Mini reviews in medicinal chemistry 2022; doi:10.2174/1389557521666210929143112 PubMed 34587883
Risk of Infection Associated With Administration of Intravenous Iron: A Systematic Review and Meta-analysis. JAMA network open 2021; doi:10.2147/PROM.S169653 PubMed 34767026