Solanum lycopersicum 'La Roma IV'
vegetableLa Roma IV is an improved hybrid paste tomato that builds on the classic Roma with a heavier, more uniform set and strong disease resistance. The compact determinate plants ripen a concentrated crop of bright red, blocky roma fruit weighing 4 to 6 oz with dense, low-moisture flesh that cooks down beautifully for sauce, paste, and canning. It matures in about 70 to 75 days and resists alternaria stem canker, fusarium wilt races 1 and 2, gray leaf spot, root-knot nematode, and verticillium wilt.
Sun
full sun
Water
Every 3 days
Harvest
~73 days
Difficulty
easy
Lifecycle
annual
One season, then done
Spacing
24-36 in. apart
Planting Depth
1/4 in. (seed) or deep-planted transplant
Soil pH
6.0-6.8
Soil Type
Rich, well-draining
Hardiness Zones
Zones 3 – 10
Grown as an annual. This range is its winter hardiness, but you can grow it for a single season in any zone.
When to Fertilize
At transplant, then every 3-4 weeks once fruit sets
Fertilizer
Balanced 5-10-10, low nitrogen after fruit set
Start seed indoors about 6 weeks before the last frost and transplant after nights stay above 50F, setting plants deep. As a determinate, La Roma IV stays bushy and sets most of its fruit over a short window, so a cage is usually enough support and the plant should not be heavily pruned, since removing suckers reduces the determinate yield. Water deeply and evenly and mulch to keep moisture steady, which is the key to preventing blossom-end rot on paste tomatoes.
Start seeds indoors
Mar 4
Transplant outdoors
Apr 29
Projected first harvest
Jul 11
Good neighbors that attract beneficial insects or deter pests
Proactive ways to stop trouble before it starts. Tap a name with an arrow for its full guide
Scout every few days and handpick caterpillars; interplant dill and borage to draw parasitic wasps
Water deeply and evenly, mulch, and keep calcium adequate
Mulch against soil splash, prune lower leaves for airflow, and avoid wetting foliage
A determinate, La Roma IV ripens most of its crop over a few weeks, about 70 to 75 days after transplant, which is convenient for putting up a batch of sauce at once. Pick the fruit when fully red and firm. The dense, dry flesh is made for cooking down into sauce and paste and holds its shape well for canning whole.
Paste tomatoes are low in calories and concentrate vitamin C, potassium, and lycopene in dense, low-moisture flesh, and cooking them into sauce with a little oil makes the lycopene more bioavailable.
Eat the ripe fruit only. Tomato leaves and stems (and large amounts of very unripe green fruit) contain solanine-type compounds and are not for eating.
For educational and informational purposes only. HomeSown is not medical, health, or other professional advice. Always positively identify any plant before handling or eating it; some plants, and some parts of otherwise-edible plants, are toxic. Consult a qualified professional before consuming or otherwise using any plant, especially if you are pregnant, nursing, taking medication, or have a health condition.