Good morning, and thank you for your question. I'm sorry that your Boston ivy looks the way it does. From an outside source, here's some pretty comprehensive diagnostic and revival information. I hope it gives you what you need to bring your plant back to its former glory. 

Note: overhead watering of any garden plant can cause fungal diseases. Root watering when plants are dry is best. \

If your plant is affected by a fungus, here's what to look for:
Leaf spots, Guignardia, Cercospora: Irregular or circular, pale tan spots with dark brown borders develop on leaves and are characteristic of infection by these fungi. 

One source recommends that a fungicide be applied soon after symptoms are visible, and recommends horticultural oil, sulfur, potassium bicarbonate, and thiophanate-methyl (consult the label for dosage rates and safety precautions.) One caution just found on thiophanate-methyl (TM) from the EPA: Low acute toxicity, but causes liver and thyroid effects in animal studies and has been classified as a probable human carcinogen.

More tips on keeping Boston Ivy healthy follow.
Jeanne

When Water Works Against You

Over-watering Woes

Yellow leaves and waterlogged soil are distress flares from your Boston Ivy. To rescue your plant from a soggy grave, ease up on the H2O. Let the soil dry out a bit before you think about giving it another drink.

If the leaves look more like a limp salad than a vibrant vine, you've gone too far with the watering can. Adjust your watering schedule—your plant's not on a swim team. Consider a well-draining soil mix and ensure your pot's drainage game is strong to avoid waterlogged misery.

️ The Thirsty Vine

When your Boston Ivy's leaves resemble potato chips, it's a clear sign of thirst. Under-watered vines droop, begging for hydration. When the soil feels like a dry martini to the touch, it's time to water.

To properly hydrate your plant, think of filling a glass—enough to satisfy, not so much that it spills over. Consistent watering is key; adapt your routine with the changing seasons. If you're unsure, the top inch of soil is your truth-teller. If it's dry, it's time to water; if it's soggy, take a break.

Light and Temperature Tango

Too Much Sun, Not Enough Fun

Leaf scorching is your Boston Ivy's way of saying it's had too much sun. If you notice leaves with crispy edges or a bleached look, it's time to intervene. Partial sun is best for hot climates, so consider relocating your vine to a north-facing or east-facing wall for some respite.

Shifting Shades

To protect your Boston Ivy from harsh rays, gradual acclimation is key. Use shade cloths or relocate the plant to a spot with indirect sunlight. Remember, it's not just about less light—it's about the right kind of light.

️ Chilly Drafts and Heat Blasts

Boston Ivy can throw a temperature tantrum when faced with inconsistent climates. Watch for wilting or leaf discoloration as signs of distress. Freezing temperatures below 0°F can damage the vine, and new growth is particularly vulnerable to late frosts.

️ Keeping the Balance

Ensure a stable environment for your vine by shielding it from extreme temperature fluctuations. Aim for the sweet spot of 65–85°F, which is ideal for your ivy. Keep it away from drafty windows and heating vents to prevent temperature-induced leaf browning or blackening.

Uninvited Guests: Pests and Diseases

Bug Battles

Pests can turn your Boston Ivy from a lush curtain to a tattered rag. Spider mites and mealybugs are the usual suspects, leaving behind webbing, spots, or their tiny bodies as evidence.

To combat these freeloaders, insecticidal soaps or neem oil are your go-to. They're like bouncers at the club door, keeping the riff-raff out. Predatory insects like parasitic wasps and predatory mites can also be enlisted; they're nature's hitmen, taking down pests from the inside out.

Fungal Fiascos and Mold Mishaps

Fungi and mold are the stealthy ninjas of the plant world, often invisible until it's almost too late. Discoloration or powdery spots on leaves are your cue to act fast.

Increase airflow and let in sunlight to cut the party short for these uninvited guests. If they're stubborn, a fungicide might be necessary. But remember, it's about changing the environment, not just a one-time fix. Keep your Boston Ivy's surroundings as inhospitable to fungi as a desert is to a fish.

Root of the Problem

Root Rot: The Silent Killer

Unearthing the issue: Signs of root rot in Boston Ivy include wilting leaves despite wet soil, and a general appearance of distress. When you suspect root rot, it's time to play plant detective. Gently remove your ivy from its pot and inspect the roots. Healthy roots are firm and white, but if they resemble overcooked noodles, you've got trouble.

Root revival: To save your Boston Ivy, snip off the rotted roots with sterilized shears—think of it as a life-saving operation. If you're left with even a small portion of healthy roots, there's hope. Repot in fresh, well-draining soil and adjust your watering habits. Remember, over-watering is like throwing a welcome party for root rot, so keep the soil moist but not soggy.