To fertilize squash successfully, test the soil, add mature compost, and feed moderately rather than automatically applying heavy doses. Apply any needed pre-plant fertilizer according to the soil-test report, then side-dress established plants when vines begin spreading, runners develop, or summer squash begins setting fruit. Keep fertilizer away from stems and leaves and water it into the root zone.
The best way to fertilize squash is to test the soil first, add mature compost before planting, and apply only the nutrients the crop and soil actually need. If additional fertilizer is warranted, apply a modest pre-plant dose and side-dress once plants are established—when vines begin spreading, runners develop, or summer squash begins setting fruit. Keep fertilizer away from stems and foliage, then water it into the soil.
As an Amazon Associate I earn from qualifying purchases.
Squash is a moderately heavy-feeding fruiting crop, but repeated heavy applications are usually counterproductive. Too much nitrogen can produce enormous leaves and vines with fewer flowers or fruit, while excess phosphorus can accumulate in the soil and contribute to water pollution.
What nutrients do squash plants need?
Squash grows best in fertile, well-drained soil with a pH of approximately 6.0 to 6.5. The plants need all three major nutrients, but their requirements are not identical:
#1 Best Overall
- OPERATION: Adjustable arm support on this seed, salt and fertilizer spreader helps provide maximum comfort
- HAND-HELD SPREADER: Perfect hand-held fertilizer, salt and seed spreader for small yards
- CAPACITY: A seed, fertilizer and salt spreader that holds up to 1,500 sq. ft. of Scotts lawn products for year-round lawn care
- USAGE: These hand spreaders for lawns are great for year-round use to seed, fertilize, salt and ice melt
- COVERAGE: These salt, fertilizer and seed spreaders for lawns are engineered for smooth, even coverage
- Nitrogen (N) supports leaves, stems, and vine growth. Too little causes pale, weak growth; too much can favor foliage over fruit.
- Phosphorus (P) supports roots and reproductive growth, but extra phosphorus should be applied only when a soil test recommends it.
- Potassium (K) supports overall plant function and fruit development. Apply it according to the soil-test recommendation rather than assuming more is better.
Utah State University classifies squash and pumpkins as intermediate-nitrogen vegetables, with a general annual requirement of about 2 to 3 pounds of actual nitrogen per 1,000 square feet in a garden setting. That figure is a planning reference, not a universal amount to apply. Existing soil fertility, compost, manure history, crop density, soil type, and the fertilizer formulation all change the correct rate.
Start with a soil test
A soil test is more reliable than choosing fertilizer by the size of the N-P-K numbers on the bag. It can identify pH and available phosphorus and potassium, and a laboratory report may provide a nitrogen recommendation or other amendment guidance.
- Test the bed before planting, particularly if you have used manure or fertilizer there repeatedly.
- Follow the report’s recommendations for lime, phosphorus, potassium, and other amendments.
- If phosphorus is already adequate or high, choose a low-phosphorus or no-phosphorus fertilizer rather than adding a “bloom” product.
- Use a soil test kit only as a preliminary check if you need a quick reading; for precise nutrient recommendations, a laboratory soil test or state Extension testing service is generally more useful.
Soil-test results are especially important because a fertilizer labeled 10-10-10, for example, contains 10 percent nitrogen, 10 percent phosphate, and 10 percent potash by weight. It does not mean that every garden should receive the same number of cups per plant.
The Tool Desk
Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Prepare the soil before planting
Squash needs fertile soil with good drainage. Before sowing or transplanting, incorporate mature compost or another well-rotted organic material into the bed. Compost improves soil structure and contributes nutrients, although it may not supply enough immediately available nitrogen for a fast-growing crop.
Do not use fresh manure around squash. Fresh manure can contain pathogens and viable weed seeds, may contain excess salts, and can injure plants. Use mature compost or properly aged, well-rotted manure instead, while observing local food-safety guidance.
Pre-plant fertilizer
If the soil test calls for fertilizer, incorporate a complete vegetable fertilizer before planting according to the report and product label. As one Utah State University home-garden example—not a universal prescription—the guidance gives 4 to 6 cups of 16-16-8 or 10-10-10 fertilizer per 100 square feet before planting.
That example should not be copied automatically. A garden that already contains adequate nutrients may need little or no complete fertilizer, while a deficient soil may require a different product or rate.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Banding fertilizer for wide-spaced squash
For winter squash and pumpkins planted at wide spacing, a fertilizer band can place nutrients near the developing root zone. Put the band beside and slightly below the seed or transplant—not directly touching it. Concentrated fertilizer salts can damage emerging roots and seedlings.
Rank #2
- 64-OUNCE BOTTLE: high-capacity poly bottle with a wide opening and easy screw top, quickly remove the lid to add your preferred seed, salt, fertilizer, etc. and simply screw back into place
- TURF AND SALT: year-round use; for steps, sidewalks and small paths in the winter; grass patches, shaded areas, gardens, and small sections the rest of the year
- 3 OPENINGS IN LID: twist lid to choose small, large and wide openings; each designed to fit different particulates like ice melt, salt, fertilizer, grass seed, sand and most pelletized products
- LARGE HANDLE: easy to grip, scoop and fill; accommodates small and large-sized hands, with or without gloves for use any time of the year
- PORTABLE: keep it on a shelf, in a closet or in the car and pull it out when it’s needed; you can even store it with product inside when not in use
When should you fertilize established squash?
Wait until the plants are established and growing actively. The practical timing varies slightly by squash type:
- Summer squash: side-dress around fruit set if the soil test, plant growth, or local recommendation supports additional feeding.
- Winter squash and pumpkins: side-dress when runners develop or vines begin spreading rapidly.
- Any squash: avoid routine feeding simply because the calendar says it is time. Feed when the crop has a demonstrated nutrient need and the label or soil-test recommendation supports it.
These recommendations from Utah State University, Oregon State University, and Minnesota Extension differ in wording but share the same principle: apply a moderate side-dressing after establishment, during the crop’s main period of vegetative expansion or early fruit production.
How to side-dress squash safely
- Confirm the need. Use the soil test, a local Extension recommendation, or a clear nutrient deficiency diagnosis. Yellow leaves can have causes other than low fertilizer, including overwatering, root damage, disease, or poor drainage.
- Measure the area. Calculate the length of the row or the square footage of the bed instead of guessing by handfuls.
- Measure one product only. Select a fertilizer and use its label rate. Do not add several fertilizers unless you have calculated their combined nutrient contribution.
- Scatter beside the plant. Place granular fertilizer around the plant’s root zone, several inches away from the stem. Do not put it on the crown, stem, or leaves.
- Respect the label. Lightly work granules into the surface only if the label allows it, especially where runoff or pets could move the product.
- Water thoroughly. Water after application so nutrients move into the root zone and concentrated granules are less likely to injure roots.
For a product-specific example, Espoma’s Garden-tone directions list summer squash among the vegetables it can be used on and direct gardeners to apply it around the drip line, keep it away from the main stem and foliage, and water thoroughly. The label provides different rates for beds, rows, single plants, and containers. Those directions apply to that product only; they are not a substitute for the instructions on another fertilizer.
Free tools Windows power users keep installed
One-click scans. No signup required.
How much fertilizer should you use?
Extension recommendations are useful examples, but they are not interchangeable. The following rates come from different publications, products, and application systems:
| Source example | Product and timing | Example rate |
|---|---|---|
| Minnesota Extension | When vines begin spreading | One-half cup of 46-0-0, or 1 cup of 27-3-3, or 31⁄2 cups of 10-3-1 per 100 feet of row |
| Utah State University | After runners develop | 3–4 tablespoons of 21-0-0 per squash plant |
| Oregon State University | Midsummer side-dressing | 1 cup ammonium sulfate, 11⁄3 cups calcium nitrate, or 1⁄2 cup urea per 10 feet of row |
These are examples for particular conditions and fertilizer formulations. Do not apply all of them, and do not convert one rate to another without accounting for the actual nitrogen percentage and the area being treated.
Calculating fertilizer from actual nitrogen
The first number on a conventional fertilizer label is the percentage of nitrogen by weight. To calculate the amount of product needed for a chosen amount of actual nitrogen:
Product required = desired pounds of actual nitrogen ÷ nitrogen fraction in the product
Crashes, No Sound, or Screen Glitches?
Random freezes, missing sound and display glitches usually trace back to one bad driver. Find and replace yours safely.Free scan · under a minutePC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11For example, a 10 percent nitrogen fertilizer contains 0.10 pounds of nitrogen per pound of product. Supplying 1 pound of actual nitrogen would therefore require 10 pounds of that product before accounting for any soil-test adjustment. A 21-0-0 product contains 0.21 pounds of nitrogen per pound, so it requires less product for the same nitrogen amount.
Rank #3
- NO ASSEMBLY REQUIRED: Scotts spreader comes pre-calibrated and ready-to-use; use it year-round including as an ice melt spreader or salt spreader for snow
- CAPACITY: Broadcast spreader holds up to 15,000 sq. ft. of Scotts lawn products, and can be used as a lawn food, salt, ice melt or grass seed spreader
- OPERATION: These fertilizer spreaders for lawns feature a hopper and agitator designed for smooth product funneling and consistent coverage
- SIDE SHIELD: Scotts exclusive EdgeGuard Technology on these broadcast spreaders for lawns keeps lawn product off landscaping, driveways, and sidewalks
- BROADCAST SPREADER: Use the Scotts Turf Builder EdgeGuard DLX Broadcast Lawn Spreader to apply Scotts lawn care products, like grass fertilizer for lawns
This calculation does not tell you how much nitrogen your garden needs. It only converts a recommended nutrient amount into a product amount. The soil test and fertilizer label remain controlling.
Organic fertilizer, compost, and fish emulsion
Organic fertilizers can work well for squash, but “organic” does not mean unlimited, immediate, or risk-free. Blood meal, alfalfa pellets, fish emulsion, composted manure, and other products differ substantially in nitrogen concentration, release speed, salt content, and application rate.
Organic nutrients often release more slowly and may require more frequent applications. Conversely, applying too much can still cause salt injury, nutrient imbalance, toxicity, or nutrient runoff. Soil microorganisms breaking down a large amount of organic matter can temporarily compete with plants for available nitrogen, particularly where substantial undecomposed material has been added.
Choose a vegetable fertilizer whose label lists squash or vegetables as an intended use, then follow the label rather than estimating a dose from another product. Split nitrogen applications instead of applying a large amount at once. Utah State University cautions against applying more than 11⁄2 pounds of actual nitrogen per 1,000 square feet in a single application.
Container-grown squash
Squash in a container has less soil and a smaller root volume than squash in the ground. It may therefore need more frequent, lower-dose feeding, especially after repeated watering has carried soluble nutrients out of the container.
- Use a container and potting mix appropriate for the size and type of squash.
- Use the fertilizer’s separate container directions; do not automatically apply an in-ground rate to a pot.
- For granular products, apply around the outer edge of the container soil or the labeled drip-line area, away from the stem.
- Water thoroughly after feeding, while ensuring the container drains freely.
Espoma’s Garden-tone label is an example of why this matters: it gives separate directions for containers as well as beds, rows, and individual plants. Product labels can differ substantially, so check the current package before every application.
Common squash-fertilizing mistakes
Using weed-and-feed in a vegetable bed
Do not use weed-and-feed products around edible squash. The herbicides may injure or kill vegetable plants. Remove weeds mechanically or use a mulch that is suitable for vegetable gardens.
Rank #4
- SEEDING MADE SIMPLE: This grass seed spreader eliminates the slow, uncomfortable struggles of using a manual spreader. With a powerful motor, it delivers an impressive max 5' spreading distance and covers up to 4600 sq. ft. per load
- SAME BATTERY, EXPANDABLE POWER: The same Power Share battery that runs this lawn spreader can conveniently be used with 140+ power tools, outdoor power equipment, and lifestyle products from the Worx Power Share platform
- PREVENTS CLOGS: Our spreaders for lawns features an anti-clog agitator to eliminate the headache of jamming up, allowing you to broadcast seed at a uniform rate and achieve proper coverage for a healthy lawn with even growth
- VERSATILE USES FOR EVERY SEASON: This cordless spreader does much more than seed lawns. Use it to spread ice-melt to de-ice pavement or apply weed control. These tools also work as fertilizer spreaders for lawns and can feed livestock
- LIGHTWEIGHT, ONE-HANDED OPERATION: Designed for ease-of-use, this lightweight spreader only weighs 3 lbs. for comfortable carrying across the yard. The handle boosts control with an easy-squeeze trigger for effortless one-handed application
Adding nitrogen whenever leaves look impressive
Large, dark-green vines do not prove that more fertilizer is needed. Excess nitrogen can encourage lush vegetative growth at the expense of fruit production and can increase the risk of runoff or salt injury.
Applying phosphorus “for blooms”
Squash does not need a high-phosphorus bloom product unless a soil test identifies a phosphorus deficiency. Additional phosphorus will not reliably solve poor flowering or fruit set when the soil already contains enough.
Putting granules against the stem
Fertilizer concentrated at the crown can injure tissue and roots. Keep granules several inches away from the stem and follow the product’s specific spacing instructions.
Assuming blossom drop means low fertilizer
Squash flowers must be pollinated. Blossom drop or small fruit that shrivels may result from poor pollination, weather, insect activity, or normal differences between male and female flowers—not necessarily a nutrient deficiency. Adding nitrogen will not correct a pollination failure.
Stacking compost, manure, liquid feed, and granular fertilizer
Each source contributes nutrients. Combining them without measuring can result in excessive nitrogen, phosphorus, salts, or runoff. Keep a simple record of what was added to the bed and when.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.A simple squash-feeding schedule
- Before planting: test the soil, adjust pH only if recommended, and incorporate mature compost.
- At planting: apply a soil-test-recommended fertilizer, if needed. Band it beside and below seeds or transplants rather than touching them.
- After establishment: inspect growth and wait for runners, spreading vines, or fruit set before side-dressing.
- Midseason: apply one moderate, measured side-dressing if the crop needs it. Use one product and its label rate.
- After feeding: water thoroughly and monitor the plants rather than automatically repeating the application.
Healthy plants with vigorous growth, normal flowering, and good fruit development may not need additional fertilizer. Good drainage, consistent moisture, adequate sunlight, and pollination are just as important as nutrients.
Choosing a fertilizer for squash
Look for a product labeled for vegetables and check its N-P-K analysis, application method, and rates for the specific situation: in-ground bed, row, individual plant, or container. A low- or no-phosphorus formula is preferable when the soil test shows that phosphorus is already sufficient.
Best Value
- NO ASSEMBLY REQUIRED: Scotts spreader comes pre-calibrated and ready-to-use with a fold-down handle for easy storage; use it year-round including as an ice melt spreader or salt spreader for snow
- CAPACITY: Broadcast spreader holds up to 5,000 sq. ft. of Scotts lawn products, and can be used as a lawn food, salt, ice melt or grass seed spreader - ideal for treating smaller areas
- OPERATION: These fertilizer spreaders for lawns feature a hopper and agitator designed for smooth product funneling and consistent coverage
- SIDE SHIELD: Scotts exclusive EdgeGuard Technology on these broadcast spreaders for lawns keeps lawn product off landscaping, driveways, and sidewalks
- BROADCAST SPREADER: Use the Scotts Turf Builder EdgeGuard Mini Broadcast Lawn Spreader to apply Scotts lawn care products, like grass fertilizer for lawns
An organic granular vegetable fertilizer such as Garden-tone can be a convenient example for gardeners who want a labeled vegetable product, but it should not be treated as the right choice for every soil or crop. The useful decision is not “organic versus synthetic”; it is whether the product supplies the needed nutrient at a label-approved rate without duplicating nutrients already present.
Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Scan for outdated or missing drivers - takes under a minute3Clear out junk files and repair common Windows errorsWhen the plant still looks unhealthy
- Pale older leaves: consider nitrogen availability, but first check watering, drainage, root damage, and disease.
- Very leafy plants with few fruits: stop adding nitrogen and investigate pollination, light, plant spacing, and excessive vigor.
- Blossoms falling without developing fruit: examine pollination and weather conditions before adding fertilizer.
- Brown leaf edges or sudden wilt after feeding: suspect fertilizer or salt injury; water deeply if drainage is good and avoid another application until the problem is resolved.
- Poor growth despite feeding: obtain a soil test rather than applying increasingly larger doses.
Frequently Asked Questions
How often should I fertilize squash?
Squash usually needs moderate feeding rather than repeated heavy applications. Test the soil first, add mature compost before planting, and side-dress only when established plants begin spreading, producing runners, or setting fruit and the soil or local recommendation indicates additional nutrients are needed.
Can I use organic fertilizer on squash?
Yes, but use a fertilizer labeled for vegetables and follow its directions. Organic fertilizers vary widely in nutrient concentration and release speed, so do not copy a rate from another product. Compost improves soil but may not provide enough immediately available nitrogen for vigorous midseason growth.
Will fertilizer stop squash blossoms from dropping?
Usually not. Blossom drop and small fruit that shrivels can result from poor pollination, weather, or normal squash flowering behavior. Extra nitrogen will not correct a pollination problem.
Where should fertilizer be placed around squash plants?
Keep granular fertilizer several inches away from the stem and foliage, scatter it around the root zone or drip line, and water thoroughly after application. For seeds and transplants, place a fertilizer band beside and below—not directly touching—the planting site.
Recommended Free Tools
The Bottom Line
Bottom line: Fertilize squash according to a soil test and the product label, not by calendar habit. Add mature compost before planting, use low- or no-phosphorus fertilizer when phosphorus is already adequate, and side-dress established plants moderately when vines spread or fruit set begins. Keep fertilizer away from stems and leaves, water it in, and remember that extra fertilizer cannot fix poor pollination.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
