Pumpkin

Direct-sow pumpkin once the soil is truly warm

Wait until all frost danger has passed and soil temperature is consistently above 70F, then sow 3 to 5 seeds 1 to 2 inches deep per hill. Space hills 4 to 6 feet apart for smaller varieties and 6 to 8 feet apart for larger ones. Pumpkins resent root disturbance and are normally direct-sown; where the frost-free season is too short, start them indoors only in plantable pots so the rootball is never broken. Pumpkin seed is a warm-soil germinator that rots rather than sprouts in cold wet ground, and the crop needs 75 to 100 frost-free days to color up, so the sowing date has to buy the whole season at once.

Side-dress nitrogen when the first fruits set

Side-dress alongside the rows when fruits first begin to develop. Scratch the fertilizer in shallowly a few inches out from the crown and water it in. Fruit set is when the plant's demand swings from building vine to filling fruit, and nitrogen delivered earlier mostly grows leaves. Feeding at set puts the nutrients where the pumpkin is actually being made.

⚠ Keep dry fertilizer off the leaves and away from the crown, and water it in.

Thin each hill to two or three plants

Once seedlings have their first true leaves, cut the weakest ones off at soil level and leave 2 to 3 vigorous, well-spaced plants per hill. Every seed in the hill was insurance against poor germination. Left standing, they crowd each other into shaded, humid growth that yields small fruit and holds leaf moisture for disease.

⚠ Cut rather than pull, so you don't tear the roots of the seedlings you are keeping.

Count cucumber beetles and squash bug egg masses

Walk the field borders first, where beetles congregate. On pumpkin the action threshold is 5 cucumber beetles per plant. For squash bug, check leaf undersides during early flowering and treat 1 egg mass per plant as the threshold. In a garden, crushing the bronze egg masses by hand is the most effective control. Cucumber beetles transmit bacterial wilt, but that disease takes hold in muskmelon and cucumber rather than squash and pumpkin, so pumpkin tolerates far more beetles before feeding damage alone justifies acting.

⚠ Do not spray an insecticide onto open pumpkin flowers. The crop depends entirely on bees, and a fruit set lost to a poorly timed spray costs more than the beetles would have.

Scout leaf undersides for powdery mildew at the 1-in-50 threshold

Starting when the first female flowers open, examine the upper and lower surfaces of five older leaves at each of 10 sites. The action threshold is one leaf with symptoms out of 50 older leaves examined. Check your most susceptible and earliest-fruiting varieties first. The fungus develops best on the lower leaf surface, where you will not see it from standing height, and finding it there is the only way to begin treatment while it can still be held. Waiting past this threshold compromises control and promotes fungicide resistance.

Powdery mildew: spray at threshold, and rotate FRAC groups

Once scouting hits one symptomatic leaf in 50, spray a targeted mobile fungicide tank-mixed with a contact protectant such as chlorothalonil, maximizing spray coverage on the leaf undersurfaces. Rotate among unrelated chemistries by FRAC code across sprays, for example a DMI (FRAC 3) such as Procure, then Vivando (FRAC 50), then Gatten (FRAC U13). Where you use a DMI, the highest label rate is recommended, because the pathogen has become less sensitive to that chemistry. A contact fungicide alone cannot reach the lower leaf surface where the fungus actually colonizes, which is why weekly protectant-only programs still end in severe mildew. Losing the leaves early leaves the fruit with soft handles, poor rind color, and sunscald.

⚠ Strains resistant to these fungicides are present throughout the United States, including New York, so never make back-to-back applications from the same FRAC group. Observe the pre-harvest interval on the product you use: Cornell lists Vivando at 0 days, Procure at 0 days, Quintec at 3 days and Proline at 7 days. PHIs and rates are legal limits set by the label of the product in your hand, which supersedes any list here.

Row-cover against squash vine borer, then pull the cover at flowering

Float row cover over the plants when the vines start to run or when you first see the moths, and seal the edges so adults cannot crawl under. Keep it on until about two weeks after the first borer is seen. Remove the cover as soon as the plants flower. Timing is regional: in the northern US there is one generation and adults emerge from cocoons in the ground in late June or early July, while southern growers see adults much earlier and a second generation, so confirm local emergence timing with your state extension rather than working from a date. There is a narrow window to act. Once a larva chews into the stem it is sealed inside where nothing sprayed on the outside reaches it, so the whole game is keeping the moth from laying on the stem base.

⚠ Never leave row cover on a flowering pumpkin. The flowers are bee-pollinated and a covered plant sets no fruit. If borers were bad last year, rotate the planting well away from that ground.

Cut when the rind is hard, then cure warm for ten days

Harvest when the fruit has a uniform orange color and a rind hard enough to resist a thumbnail. Cut, don't tear, leaving a 3- to 4-inch handle of stem. Cure at 80 to 85F and 80 to 85 percent relative humidity for about 10 days, then store at 50 to 55F in a cool, dry, well-ventilated place. Curing hardens the rind and heals cuts and scratches that would otherwise be the entry wound for the rots that hollow a pumpkin out in storage. Cured and stored properly, fruit holds 2 to 3 months.

⚠ Get the fruit in before a hard freeze. A light frost destroys the vines without harming the pumpkins, but never carry a pumpkin by its handle, as a snapped stem is an open wound and the fruit will not keep.