A windowsill winter rules out the pomegranate before you've compared anything else. Lemon (Citrus limon) is the one of these two that can come inside for the cold months, and even the lemon needs a grow light to do it well. Pomegranate (Punica granatum) is an outdoor tree that must drop its leaves and rest for six to eight weeks somewhere cold; a heated room in January is exactly what it can't have.
Give both a patio in full sun from spring to fall and the question flips. Pomegranate flowers on schedule, sets miniature fruit that fits the tree, and asks for nothing more exotic than a cold garage. Lemon flowers too, and then grows a full-size lemon that outweighs the branch holding it, on a diet of citrus fertilizer with iron, zinc, and manganese.
Both are rated intermediate. Only one of them can come inside in winter.
| Attribute | Lemon | Pomegranate |
|---|---|---|
| Difficulty | Intermediate, indoor-capable | Intermediate, needs dormancy |
| Environment | Outdoor, indoors in winter | Outdoor only |
| Light | Full sun, 6-8 hours | Full sun, 6-8 hours |
| Water | Let top inch dry | Moderate, let top dry |
| Growth Rate | Moderate grower | Moderate grower |
| Mature Size | 12-24 inches | 8-20 inches |
| Best Styles | Informal upright, broom | Informal upright, literati, root-over-rock |
| Price Range | $30-60 starter | $15-30 starter |
Winter placement is the deciding difference. Lemon is listed for indoor and outdoor growing because it can spend the cold months inside, in a south window plus a few hours of grow light, ideally resting at 50-60°F. Move it in gradually over two weeks or it drops most of its leaves. Pomegranate has no indoor option: it needs six to eight weeks of cold dormancy, an unheated garage at 20-45°F is the model, and a warm room gives you weak spring growth and few flowers.
Fruit scale is the funny part. A lemon does not shrink to match the tree; a 16-inch lemon bonsai can't ripen five fruit, so you thin to one or two while they're pea-sized and prop the branch that carries them. Pomegranate fruit is miniature, and on the dwarf 'Nana' the flowers and fruit stay proportioned to a 12-inch tree. Both are edible, though bonsai pomegranates are mostly seeds.
Money and the dog both point to pomegranate. The lemon side of the ledger: a 2-3 gallon Meyer from a garden center is $30-60 and beats anything labeled a lemon bonsai at twice the price, trained lemon bonsai are rare at $200-600, and the tree is toxic to pets. Pomegranate's 'Nana' starts at $15-30, trained trees top out around $250, and it's rated pet-safe.
Sun requirements match on paper and differ in kind. Both want six to eight hours of direct light, and neither flowers on less. Pomegranate needs summer heat as well: a south wall radiating warmth in the afternoon is the standard trick, and a cool summer means poor bloom regardless of hours. Lemon's trouble is the other end of the year, when a dim heated room turns it into long pale shoots with no flowers.
Feeding is where lemon gets specific. It wants a citrus fertilizer with iron, zinc, and manganese every two weeks from March through October; a generic balanced feed produces yellow leaves with green veins within a season. Pomegranate takes balanced feed every two weeks and a switch to low nitrogen once buds show. Watering follows suit: lemon waits for the top inch to dry, about every 2-3 days outdoors; pomegranate waters at a dry top half-inch, every 1-2 days.
Cold tolerance is a bigger gap than the zone numbers suggest. Lemon is a zone 9-11 tree, hardy to about 25°F in the ground, with the pot sheltered below about 40°F. Pomegranate is a zone 8-10 tree, hardy to 10°F in the ground, with the pot protected below about 30°F. Those ten degrees, plus lemon keeping its leaves year-round, are why one winters in a garage and the other in your living room.
Pick the pomegranate if the tree can live outside from spring to fall and you have somewhere cold and unheated for winter. It fruits in proportion, needs no special fertilizer, costs half as much, and won't hurt the dog.
Pick the lemon if winter has to happen indoors and you'll pay for a grow light and citrus fertilizer, or if you want the joke of a real lemon on a 16-inch tree. Buy neither for a north-facing window or a dim apartment: both need six to eight hours of direct sun, and without it you get a leggy green plant that never blooms. A ficus is the tree for that room.
