Success with Growing Eggplants

We are about to transplant our eggplants, so I can tell you all about it. I’ll skip over the details of sowing, assuming you’ve already done that. After the growing info, I’ll summarize our variety trials in case you are considering which to grow next year. If you already grow more than one variety, I encourage you to track how each one does, to refine your future plans.

Eggplant Crop Requirements

Eggplants benefit from fertile, well-drained soils high in organic matter, with a pH of 6.0-7.0, with 6.0-6.5 ideal. Average moisture with plenty of warmth and sunshine are needed. Ideal daytime growing temperatures are 70-85°F (21-29°C).

Care of Young Eggplant Starts

You may have sown in plug flats or pots, or in open flats. You will probably have potted up the plants into 3-4” (7.6-10 cm) pots. We keep ours away from doors in the greenhouse in the cozy south-west corner. Protect the seedlings from flea beetles, as well as drafts, either in the greenhouse or on benches outside. Flea beetles cruise at low altitudes, so setting your flats 3’ (1 m) above the ground may be all you need to do to keep them away. Or you may need netting. Johnny’s Selected Seeds has 6.9’ x 328’ ProtekNet for $375. They say:

“ProtekNet netting keeps insects as small as flea beetles and thrips off tender crops while providing maximum ventilation to prevent heat stress on hot summer days. Fine synthetic knitted mesh is UV resistant and lasts 1–3 seasons. Easy to see through, so crops can be inspected without removal. For best results, use over Quick Hoops or Wire Support Hoops, bury the edges, and ensure foliage is not touching the net, so insects can’t lay eggs through it. 0.0138″ x 0.0138″ (0.35 mm x 0.35 mm) mesh. 89% light transmission; 62% porosity; Weight: 0.74 Oz. per sq.yd. NOTE: Cut netting longer than needed to accommodate shrinkage.”

 

Gardeners Edge (AM Leonard) has 6.9’ x 32’ of the same mesh size for $58.94

The Dubois Agrinovation US website offers several nets with mesh small enough (0.0138″ x 0.0138″ /0.35 mm x 0.35 mm) to keep out flea beetles: 25g, 47g, 56g, and 70g. Some are more durable than others, naturally. 164ft rolls cost from $198.32. We have found ProtekNet to more durable than rowcover.

Transplanting Eggplant

Plant spacings of 18-24” (45-60 cm) in-row and 30-36” (76-91 cm) between rows are usually recommended – or more to accommodate machinery. We used to grow two staggered rows in our 4’ (1.2 m) wide beds, aiming to have the plants 30” (76 cm) apart. This created crowded aisles, so we now plant a single row in each bed, with in-row spacing of 20-24” (50-60 cm), creating a “hedge” and leaving the paths more accessible. This fits with the approach that considers the area each plant has, rather than the intensive planting approach that favors equal space in all directions.

To harden off for planting out, reduce moisture rather than dropping the temperature, as this crop is easily stunted by cold temperatures. Ideally, keep eggplants above 55°F (13°). Transplant the 8-12 week old plants 1-2 weeks after the last frost date, in a warm spell. The transplants should be 6-10” (15-25 cm) tall, without any buds, flowers or fruit. We leave our eggplants to be one of the later crops set out, after tomatoes and peppers. To help warm the soil, you could spread black plastic mulch two weeks before transplanting. This will also deter flea beetles. Avoid organic mulches at planting time, as they cool the soil. In cool climates, rowcover on hoops is a good idea for new transplants, to keep the plants warm. Fine mesh netting will keep flea beetles away.

Our technique for minimizing flea beetles while transplanting is to set out hoops, and sticks to hold the netting down on either side of the bed. The rolled netting is at the ready. One or two people transplant, and a third person with a hose and spray-head gives the plants a strong spray, directing the flea beetles out of the bed. A fourth person follows close behind, unrolling the netting and battening it down quickly after each plant.

Caring for the Eggplant Crop

Once the soil is fully warm, you can cultivate and spread organic mulch. Because the plants will be in the ground for a long season, and organic mulches break down, we use our eggplant beds as convenient places to drop off finished crop residues or weeds – only healthy, non-seeding material of course. In hot dry weather, weeds can be pulled from the mulch and laid on top to die.

Any stress from cold weather, disease, or low fertility will cause eggplant skins to thicken and become bitter. If your soil fertility is low, feed monthly with fish emulsion, or side-dress with compost. Don’t overdo the nitrogen or you will get lots of leaves but few fruit.

We don’t usually stake ours, but if your area is windy, you could stake tall varieties, with 3-5’ (1-1.5 m) stakes every third plant around the perimeter and twine every 12” (30 cm) up the stakes to corral the bushes. Upright bushes may produce better shaped fruit. When the branches threaten to take over the aisles, snip them off as you harvest.

Some growers pinch out the growing tips to encourage branching, although ours branch just fine without, and I hate removing bits of healthy crop plants. Conversely, growers in cooler climates sometimes prune low branches and leave just two main stems to be sure of getting some ripe fruit. In the fall, if rowcover is used to keep the first few frosts off, the big plants can ripen existing fruits. No new fruit will set once the temperature drops below 70°F (21°C).

As with most crops, the critical time for irrigation is during flowering and fruit formation. Insufficient water during this stage can lead to blossom end rot, misshapen fruit and reduced yield.

The above information is from my book Sustainable Market Farming. In the eggplant chapter you can find more about sowing, crop rotations, pests and diseases, harvesting, storage and seed saving

Eggplant Variety Trials

Most of my prior posts about eggplant have been about the years of variety trials we did from 2013 to 2016.

In December 2012, I wrote about trying new eggplant varieties

Back at the beginning of the 21^st century, we had tried lots of different eggplant varieties, and found that Nadia consistently did best. After the hot summer in 2012 when our Nadia eggplant refused to set fruit in the heat, I started looking for heat-tolerant varieties. For a while in early summer 2012 the Nadia didn’t grow at all – no new flowers, never mind new fruit.  We chose large purple-black tear-drop shaped eggplant because that’s what our cooks want.

We didn’t include any green, striped, long skinny, orange, fluted or other unusual kinds. No judgment about people who like those! I looked at growing some combination of Nadia (67d, good set in cool conditions) with of

• Epic F1 61-64d (early and huge!). Recommended in Florida and Texas.
• Night Shadow F1 68d, (size claims vary from “similar to Epic” to “smaller.
• Traviata F1 (variously recorded as 55-60d, 70d and 80d), small but good flavor. Recommended in Florida.
• Irene F1 (mid-early). Large, shiny purple, traditional-shaped fruit 5″ x 6-7″. Great flavor, big plant, productive.
• Classic F1 76d, heavy yields, high quality, does not perform well in cool conditions. Recommended in Florida and Texas.
• Santana F1 80d, large, continuous setting. Recommended in Florida.
• Florida High Bush OP 76-85d, reliable, large fruit, drought and disease resistant. Recommended in Florida and Texas.
• Florida Market OP 80-85d, large, excellent for the South, not for the Northeast. Recommended in Florida and Texas.

In 2013, alongside Nadia, we trialed: Florida Highbush, Epic and Traviata. Ironically, the summer of 2013 was not hot. One of the coolest we’ve had in a long time. We did a final harvest in preparation for our first frost, Sunday October 20/21, and I crunched the numbers. We planted 38 Nadia, 10 Florida Highbush, 10 Traviata and 12 Epic. Harvests started on July 25, later than our usual July 10, because of the cool weather. We harvested three times a week until 10/17. I was surprised how few fruit each plant provided – about 6. Initially, Nadia was providing by far the largest fruit, with Florida Highbush the smallest. Traviata doesn’t claim to be big. In the first week of harvests, Nadia produced most per plant, but this leveled off pretty soon. Final figures were 7.3 fruits/bush for Traviata, 6.3 for Florida Highbush, 6.1 for Nadia, and only 4.4 for Epic. We realized that we had stunted the Epic unintentionally by planting it at the stony end of the bed, near the road.

In 2014, we grew the same four varieties, to test them in a hot summer. But again it didn’t get hot! All four varieties have similar-sized fruit. We did better record-keeping, and found that the size and weight of each fruit was very similar across the varieties, varying only from Epic’s 0.61 lbs to Traviata’s 0.64 lbs per fruit average. Nadia yielded best per plant, at 13.4 fruits over the season. Epic was next at 12.5 fruits, then Traviata with 11.7 fruits. Florida Highbush was a poor fourth with an average of only 6.8 fruits per plant.

In 2015, we still did not get a hot summer! We had added a fifth variety for 2015: Florida Market, (like Florida Highbush, this is also open-pollinated.). By late august, Epic was winning, at 4.1 fruits and 3.4 pounds per plant, with an average of 0.84 pounds per fruit. Traviata was running second, at 3.1 fruits and 2.4 pounds per plant (average of 0.79 pounds per fruit). Nadia was third, at 2.3 fruits and 1.8 pounds per plant (average 0.75 pounds per eggplant). Florida Highbush (yes, it is a tall plant!) was beating Nadia on tonnage (2.1 pounds/plant) but losing on size (in other words, more, smaller eggplant). Florida Market was trailing, with many days providing no harvest. Our final figures for 2015 showed Florida Market’s fruits were smaller and rounder, and it had a lower yield. It was at the dry stony end (so unfair!) Epic did best, both in number of fruit/plant (10.7) and weight per fruit (0.77 lbs). Good thing we didn’t give up on it after 2013! Traviata provided 8.9 fruits/plant, Florida Highbush 8.2, Nadia only 8.0 (we did get a lot of culls too), and the Florida Market just 7.5.

In 2016,  we actually had some hot weather! We dropped the OPs and planted only the higher yielding Epic, Traviata, and Nadia. The September assessment showed of the three, Epic was winning! From the first harvest on 7/18, up to the end of August, Epic had produced a staggering 287 eggplants, averaging 0.9 pounds each; Nadia, 125 eggplants, averaging 0.76 pounds each; Traviata, 124 averaging 0.72 pounds. That year we also logged the cull rate: Nadia was best (least) at 21%; Epic was close at 22%, while Traviata produced a surprisingly high proportion of culls at 29%. During September, Traviata produced the largest number of saleable fruits (145) compared to 138 Nadia and 135 Epic. Probably not statistically different from each other. As I’ve noted before, the eggplants are all a similar size, and so it’s no surprise that Traviata’s 145 fruits totaled the highest weight (112.5 pounds), with Nadia at 98 pounds and Epic at 95.5. Nadia had an 8% cull rate, Traviata 9% and Epic only 6.8%. Clearly, all three are good varieties.

Adding September to the figures for August and July, Epic was the winning eggplant in terms of total yield, saleable yield, low cull ratio, and weight per fruit. That impressive leap off the starting blocks that Epic made was still holding it ahead of the pack. The ripe fruits got a little smaller, and there was been a noticeable drop-off in yield since the equinox.

After that, we grew Nadia and Epic, to cater for both types of summer. Recently some cooks developed an interest in Ping Tung Long, so we have been growing that as well as Epic.