Fruits & otherRhubarb
Rheum × hybridum
Garden rhubarb is a hardy perennial usually grown from crowns, planted in early spring in full sun and spaced 3 feet (91 cm) apart. Only the stalks are eaten; the leaves are toxic.
How to grow rhubarb
Side by side
Pick two or three seeds to see how they grow, side by side: sprouting, spacing, sun, water, frost and pet safety in one table.

Comparing Rhubarb vs. Buckwheat
The comparison
| Fact | ![]() | ![]() |
|---|---|---|
| Difficulty | Easy | Easy |
| Life cycle | Perennial | Annual |
| Germination time | Not yet verified | 3–4 days |
| Sowing depth | Not yet verified | 1.5–2.5 cm½–1 in |
| Spacing between plants | 91 cm3 ft | Not yet verified |
| Sun | Full sun | Full sun, partial shade |
| Water | Moderate | Not yet verified |
| Toxicity to cats | Toxic | Toxic |
| Toxicity to dogs | Toxic | Toxic |
| Links |
Up close
What each one is, in a few lines, with the full growing guide one click away.
Fruits & otherRheum × hybridum
Garden rhubarb is a hardy perennial usually grown from crowns, planted in early spring in full sun and spaced 3 feet (91 cm) apart. Only the stalks are eaten; the leaves are toxic.
How to grow rhubarb
Fruits & otherFagopyrum esculentum
Buckwheat is a fast-growing summer annual whose seeds sprout within 3 to 4 days and can be cooked as a grain.
How to grow buckwheatKeep comparing
Add a third seed, or swap one for a close relative from the same category.


Rhubarb vs. Buckwheat vs. AlfalfaAdd alfalfa as a third

Rhubarb vs. Buckwheat vs. American PersimmonAdd american persimmon as a third

Rhubarb vs. Buckwheat vs. Apple TreeAdd apple tree as a third
Rhubarb vs. AlfalfaRhubarb against another seed
Buckwheat vs. AlfalfaBuckwheat against another seed
Rhubarb vs. American PersimmonRhubarb against another seedThe table, row by row
Every row is a fact from each seed's own profile, lined up so the differences stand out.
Germination time and temperature
How many days the seeds take to sprout, and the temperature range they sprout in.
Sowing depth and spacing
How deep to sow each seed and how far apart the plants should grow. “On the surface” means the seed isn't covered.
Days to maturity and life cycle
How long until the plant is ready, counted from sowing or from transplanting (each value says which). Annuals live one year, biennials two, perennials longer.
Sun and water
Full sun means 6 or more hours of direct sun a day, partial shade a few hours. Water needs are rated low, moderate or high.
Containers, frost tolerance and soil pH
Whether it grows in a pot, with the smallest pot when it's known. Frost tolerance runs from tender (no frost) to hardy. Soil pH 7 is neutral.
Toxicity to cats and dogs
Whether the plant is toxic to cats and dogs.
Quick wins
Days from sowing until the first shoots appear, in good conditions.
Pet friendly
Listed as non-toxic to both cats and dogs. Each seed's page has the details.
Not safe for pets: borage, buckwheat, caraway, carnation and 14 more.
Comparing
Each seed's page explains how to grow it from seed, with facts researched and reviewed by our editors.